<s> [INST] <<SYS>> You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information. <</SYS>> What is Plasma cell dyscrasias and explain in detail? [/INST] Plasma cell dyscrasias (also termed plasma cell disorders and plasma cell proliferative diseases) are a spectrum of progressively more severe monoclonal gammopathies in which a clone or multiple clones of pre-malignant or malignant plasma cells (sometimes in association with lymphoplasmacytoid cells or B lymphocytes) over-produce and secrete into the blood stream a myeloma protein, i.e. an abnormal monoclonal antibody or portion thereof. The exception to this rule is the disorder termed non-secretory multiple myeloma; this disorder is a form of plasma cell dyscrasia in which no myeloma protein is detected in serum or urine (at least as determined by conventional laboratory methods) of individuals who have clear evidence of an increase in clonal bone marrow plasma cells and/or evidence of clonal plasma cell-mediated tissue injury (e.g. plasmacytoma tumors). Here, a clone of plasma cells refers to group of plasma cells that are abnormal in that they have an identical genetic identity and therefore are descendants of a single genetically distinct ancestor cell.
At one end of this spectrum of hematological disorders, detection of one of these myeloma proteins in an individuals blood or urine is due to a common and clinically silent disorder termed MGUS, i.e. monoclonal gammopathy of undetermined significance. At the other end of this spectrum, detection of the myeloid protein is due to a hematological malignancy, i.e. multiple myeloma, Waldenström macroglobulinemia, or other B cell-associated neoplasm, that has developed, often in a stepwise manner, from their MGUS precursors.The clinical importance of understanding this spectrum of diseases is that it can be used to: a) advise individuals on the likelihood of their condition progressing to a malignant phase; b) monitor individuals for the many complications that may occur at any stage of the dyscrasias so that they can be treated to avoid or reduce their clinical impacts; and c) monitor patients for transitions to malignancy so that the malignancy can be treated at an early stage when treatment results are best. Unless otherwise noted, the advice and monitoring given here are those recommended by the International Myeloma Working Group in 2014 and updated in 2016.

Clonal plasma cells
Plasma cells are key effector elements of the adaptive immune system. They contribute to immunity by making antibodies that bind with and thereby initiate the process of neutralizing specific antigens that usually are found on the surface of invading pathogens and foreign substances. Plasma cells develop from B lymphocytes (i.e. B cells) which are stimulated to undergo this maturational development by T lymphocytes during the latter cells processing of these antigens. As they are stimulated to become plasma cells, B cells refashion parts of their genome in efforts to create a new gene that encodes a functional antibody. In humans, antibodies are composed of two identical heavy chains which are of the gamma (γ), alpha (α), epsilon (ε), delta (δ), or mu (μ) subtypes and two identical light chains which are of the kappa (κ) or lambda (λ) subtypes. Antibodies are classified as IgG, IgA, IgE, IgD, and IgM based on their being made up of γ, α, ε, δ, or μ heavy chains, respectively. Formation of the genes that make these antibodies requires B cells and/or their descendent plasma cells to mutate, break, and recombine various genes at the immunoglobulin heavy chain antigen-binding locus on the long (i.e. "q") arm of human chromosome 14 at position 32.33 (notated as 14q32.33) and the immunoglobulin light chain antigen binding locus on the q arm of chromosome 22 at position 11.2 (i.e. 22 q11.2) by processes termed V(D)J recombination, somatic hypermutation, and immunoglobulin class switching.  These genomic changes can go awry by placing a gene that controls cell growth an/or survival adjacent to a normally highly active antibody gene promoter and/or by causing the formation of extra chromosomes (see trisomy) or chromosomes with large deletions that result in the overexpression or under-expression, respectively, of genes that control cell growth and/or survival. In consequence of these "primary genomic changes", an expanding clone of cells develops; overproduces and secretes a monoclonal IgM, IgG, IgA, IgE, or IgD antibody, a κ or λ light chain, an α, γ, or μ heavy chain, or, very rarely, fragments of these proteins; and may accumulate "secondary genomic changes" that cause them to become malignant. The overproduced monoclonal proteins, termed myeloma proteins, commonly circulate in blood, may accumulate in urine, and are the hallmarks of plasma cell dyscrasias including their most malignant forms viz., multiple myeloma, light chain multiple myeloma, and plasma cell leukemia. IgG-secretory, IgA-secretory, and light-chain secretory multiple myeloma represent 52%, 21%, and 16%, respectively, of all multiple myeloma cases; these myelomas are associated with various types of chromosomal aberrancies and mutations. IgD-secretory multiple myeloma occurs in only 1% to 2% of multiple myeloma cases and is commonly associated with somatic mutations in the gene encoding the gV (i.e. variable) region of the monoclonal antibody. IgE-secretory multiple myeloma has been reported in <50 cases as of 2013 and is characteristically associated with translocations between the q arms of chromosome 11 and 14, i.e. t(11;14)(q13;q32) translocations.In other cases, plasma cells and/or lymphoplasmacytoid cells (a type of B cell resembling, and possible precursor to, plasma cells) suffer other kinds of mutations that lead to the production of an IgM myeloma protein. Overproduction of this myeloma protein may progress to a different form of plasma cell/lymphoplasmacytoid cell malignancy, Waldenström macroglobulinaemia. Genetic mutations thought to be involved in the development and/or progression of the latter disease include the L265P mutation in the MYD88 gene found in >90% of Waldenström macroglobulinaemia patients as well as various mutations in the CXCR gene found in 27% to 40% of Waldenström macroglobulinaemia patients.The clonal plasma cells involved in plasma cell dyscrasias exhibit a high degree of genetic instability. For example, the clonal plasma cell population formed by initial genetic alterations that lead to multiple myeloma contains cells that develop further genetic changes that enhance their survival, proliferation, tissue-injuring, and metastatic capacities. This allows the new cell clones to crowd out older cell clones and thereby  establish a more malignant disease. Repetition of such genetic changes underlie the evolution of a clinically silent plasma cell dyscrasia to an overt malignancy. The progressive genetic changes in clonal plasma cells include accumulating numerous single nucleotide polymorphisms, increases and decreases in gene and chromosome copy numbers, and chromosomal translocations. Genes affected include those regulating genome stability itself (e.g. KIF2B) as well as cellular activation, proliferation, and apoptosis (e.g. CIDEC, TP52, ATM, KRAS, NRAS, Wnt, and NF-κB). In the most malignant form of plasma cell dyscrasias, primary plasma cell leukemia, the plasma cell population contains >1900 distinct DNA alterations in >600 genes.In general, the plasma cell dyscrasias are defined by 1) the presence of these genetically unstable clonal plasma cells, lymphoplasmacytoid cells, or B cells infiltrating the bone marrow or forming distinct masses in bone, and/or other tissues as defined by biopsy of involved tissues and 2) the presence of these cells myeloma proteins (i.e. intact monoclonal antibody, free light chain, free heavy chain, shortened version of these proteins, or any combination of these proteins) in blood and/or urine as defined by various types of gel electrophoresis. Obviously, the latter criterion does not apply to the rare cases of true non-secretory myeloma.

Myeloma protein toxicity
Myeloma proteins form as a result of gene mutations rather than physiological gene remodeling responses to an instigating foreign antigen: typically these proteins are non-functional. However, they  sometimes cause serious tissue damage with the kidney being a particularly vulnerable target. The toxic effects of monoclonal proteins may occur at early stages in the plasma cell dyscrasia spectrum and require treatment independently of the mass or tissue-destructive effects of the myeloma protein-producing cells. Myeloma protein toxicities include:

Monoclonal free light chains, free heavy chains, or a mixture of these chains can deposit in the kidney and other organs to cause systemic monoclonal immunoglobulin deposition disease; free κ or λ light chains can deposit selectively in the kidneys proximal tubule to cause light chain proximal tubulopathy or in the kidneys distal tubule to cause light chain myeloma cast nephropathy; and various myeloma proteins can deposit selectively in the kidneys glomeruli to cause various forms of organized deposit and non-organized deposit glomerulonephritis diseases.
Free κ or λ light chains can aggregate with each other to cause extracellular amyloid deposits and a disease termed amyloidosis in which the deposits injure and ultimately lead to the failure of such organs as the kidney, heart, liver, stomach, and intestines; these deposits can also cause peripheral and autonomic neuropathies.
IgM myeloma proteins or in rare cases other myeloma proteins such as IgA, free κ light chains, or free λ light chains may increase blood viscosity, deposit in peripheral blood vessels, and thereby cause vascular occlusion and gangrene of the extremities in the syndrome termed cryoglobulinemia.
Monoclonal IgM myeloma proteins operating through their effects on increasing blood hyperviscosity can reduce blood flow to the central nervous system to cause blurred vision, headaches, vertigo, ataxia, and cold-induced hemolytic anemia.
IgM, IgG, and to lesser extents κ and λ free light chain myeloma proteins can cause Immune thrombocytopenic purpura with extensive bleeding tendencies .

Stages
MGUS stage
Monoclonal gammopathy of undetermined significance (MGUS), is defined as the presence in the blood or urine of a monoclonal antibody, antibody heavy chain, or antibody light chain in a person lacking symptoms or signs of a more serious plasma cell dyscrasia. The condition is typically discovered as an incidental finding when serum protein electrophoresis is done for various reasons unrelated to plasma cell dyscrasias. Protein electrophoresis generally detects one of the following patterns of monoclonal myeloma protein spikes representing: a) intact IgG, IgA, IgE, IgE, or IgM; b) intact IgG, IgA, IgE, IgD, or IgM plus high concentrations of a free (i.e. not bound to a heavy chain) κ or λ light chain; c) a free κ chain in great excess of a λ chain or a free λ chain in great excess of a κ chain; and d) free γ, δ, or μ heavy chains unbound to a light chain (free α and ε heavy chain myeloma protein spikes have not been reported). Among MGUS cases expressing an intact antibody, 70%, 15%, 12%, and 3% express either IgG, IgM, IgA, or two of these M proteins, respectively, with or without excessive levels of a light chain; these cases represent ~80% of all MGUS. About 20% of MGUS cases express either κ or λ light chains. As a group, these MGUS findings occur more commonly in men and are ~2-fold more common in individuals of African descent than Caucasians. MGUS cases expressing free γ, δ, or μ heavy chains are extremely rare. MGUS is categorized into the following sub-types based upon the identity and levels of the myeloma proteins detected as well as the prognoses for progressive disease indicated by these myeloma protein findings.

Non-IgM MGUS
Non-IgM MGUS, commonly termed MGUS, is diagnosed in individuals who exhibit a serum IgG, IgD, IgA, or IgE monoclonal protein with or without increased levels of blood and/or urine free κ or λ light chains. These patients typically also show small increases in bone marrow plasma cells. Further requirements for the diagnosis of non-IgM MGUS are: a) bone marrow clonal plasma cells <10% of total nucleated cells; b) absence of any of the four CRAB criteria (CRAB criteria are C = Calcium serum levels >1 milligram/deciliter above normal values and/or a serum level >11 milligram/deciliter; R = Renal insufficiency as defined by a glomerular filtration rate <40 milliliter/minute and/or a serum creatinine >2 gram/deciliter due to myeloma protein-induced kidney damaged; A = Anemia, as defined by a  blood hemoglobin level >2 gram/deciliter below normal and/or <10 gram/deciliter due to the plasma cell dyscrasia rather than e.g. iron deficiency or blood loss; B = Bone lesions, i.e. ≥1 lytic (i.e. bone re-adsorbing) bone lesion due to a plasmacytoma as detected by skeletal radiography, computed tomography, or positron emission tomography-computed tomography); c) no evidence of a plasmacytoma in bone or soft tissues, of amyloidosis, or of another plasma cell disorder; d) a ratio of free serum light chains (i.e. free κ/λ or λ/κ light chain ratio) less than 100, providing that the higher light chain concentration is >100 milligram/liter; and e) a circulating blood plasma cell absolute count of <2x109 and/or <20% of total circulating nucleated cells. Presence of any one of the latter findings indicates that the plasma cell dyscrasia has progressed beyond the MGUS stage.Non-IgM MGUS is a relatively stable condition afflicting 3% of people aged 50 and 5% of people aged 70; on average, it progresses to multiple myeloma at a rate of 0.5-1% cases per year, as defined in studies following patients over a 25-year period. A study conducted by the Mayo Clinic found that MGUS associated with non-IgG myeloma proteins or with serum myeloma protein levels greater than 15 gram/liter had a greater risk per year of progression to multiple myeloma. A Spanish study group found that MGUS patients demonstrating aneuploidy (i.e. abnormal number of chromosomes) in bone marrow cells or >95% of resident bone marrow plasma cells that are clonal in nature also have a greater risk per year of progression to myeloma. In a more recent study, MGUS patients that had the presence of none, 1, 2, or 3 of the three following risk factors, serum M protein levels >15 gram/liter, a non-IgG isotype, and abnormal free light chain ratios, had 5, 32, 37, and 58% chances, respectively, of progressing to multiple myeloma within 20 years. In another study, MGUS patients with none, 1, or 2 of the following risk factors, >95% of bone marrow plasma cells that are clonal in nature and a 10% or greater rise in the levels of their monoclonal proteins within 3 years, had 2, 16, and 72% risks, respectively, of progression within 7 years. However, estimates on the risks of progression for some of these parameters are tentative and subject to change. For example, the IgA form of MGUS, while once considered to have a poorer prognosis than IgG MGUS, was found to have a prognosis similar to IgG MGUS in a more recent study.

IgM MGUS
While traditionally classified as such, it is not clear that IgM MGUS is a clonal plasma cell dyscrasia. IgM MGUS involves an increase in a B cell derivative with morphological features of both plasma cells and lymphocytes viz., lymphoplasmacytic  cells. Studies indicate that both plasma cells and lymphoblastic cells infiltrate involved tissues and that one or perhaps both cell types harbor mutations in a) the MYD88 gene (~20% in IgM MGUS and >90% in IgM-related malignancies), almost all of which are L265P mutations (i.e. changing leucine to proline at the 265th amino acid position of the MYK88 protein thereby causing the protein to be continuously active in stimulating the same cell-activating pathways that Toll-like receptors activate intermittently and on a  physiologically basis); b) the CXCR4 gene (8% in IgM MGUS, 25% in IgM-related malignancies); and c) increased gene copy number due to chromosomal rearrangements (36% in IgM MGUS, 82% in IgM-related malignancies). It is clear that each cell type contributes to different features of IgM malignancies but not clear that clonal plasma cells are critical to the development or progression of IgM MGUS. In all events, IgM MGUS is diagnosed in individuals who have serum IgM levels less than 30 gram/liter; have less than 10% of nucleated bone marrow cells with the lymphoplasmacytic morphology, and have no symptoms or findings of end organ dysfunction attributed to Waldenström macroglobulinemia such as anemia, decreases in any white blood cell count, cold agglutinin disease, hyperviscosity of blood, lymphadenopathy, hepatomegaly, splenomegaly, peripheral neuropathy, cryoglobulinemia, or constitutional symptoms.There may be a modest increase in the incidence of IgM MGUS in people of African descent. A study of 213 individuals diagnosed with IgM MGUS found that 10% at 5 years and 24% in 15 years progressed to more serious IgM-related diseases including non-Hodgkin lymphoma, Waldenstorms macroglobulinemia, systemic amyloidosis, and chronic lymphocytic leukemia. A second long-term study of 116 individuals with IgM MGUS found a 15-fold increased risk of progressing to a lymphoid malignancy, mostly to Waldenstorms macroglobulinemia. In general, progression to one of these malignant outcomes occurs at a rate of 2% to 3% per year. Individuals with higher serum IgM or lower serum albumin levels progress at faster rates than those with normal levels of these parameters.

Light chain MGUS
Individuals diagnosed with light chain MGUS typically do not express detectable levels of an IgG, IgA, IgD, IgE, or IgM intact myeloma protein in their blood. Rather, they overexpress a monoclonal, aberrant free κ (i.e. kappa) or λ (i.e., lambda) immunoglobulin light chain. For diagnosis, the κ and λ free light chains are quantified by immunological methods and the ratio of κ to λ light chains is used to detect unbalanced light chain synthesis that is indicative of a monoclonal light chain plasma cell dyscrasia. Light chain MGUS is defined as a disorder in which a serum κ to λ free light chain ratio falls outside the normal range of 0.26–1.65 (mean =0.9) provided that it is not associated with: a) any of the CRAB criteria, b) a bone marrow plasma cell count of 10 or a higher percentage of nucleated cells, c) evidence of amyloid deposition (see Light chain deposition disease), and d) an accumulation of 0.5 or more grams of the monoclonal light chain in the urine over a 24-hour period. As so defined, light chain MGUS comprises ~19% of all MGUS cases, occurs in ~0.8% of the general population, and progresses to light chain multiple myeloma at the very slow rate of 0.3 cases per 100 years.Some early studies have reported that a very rapid rate of progression occurs in light chain MGUS patients who have free light chain κ/λ or λ/κ ratios equal to or greater than 100 (i.e. and κ/λ ratio outside of 0.02 to 100). About 80% of individuals bearing these light chain ratios were found to progress to light chain multiple myeloma within 2 years. In consequence, these individuals were recommended for being diagnosed and treated as having light chain multiple myeloma. However, two more recent studies reported a 2-year progression rate for these patients of 64% and 30%. It is therefore suggested that the diagnosis of light chain multiple myeloma based solely on a free κ/λ light chain ratio of 0.02 to 100 may be premature.

Monoclonal gammopathy of renal significance
Monoclonal gammopathy of renal significance or MGRS designates any MGUS disorder that has a clinically significant impact on renal function. MGRS can be caused by the deposition of a monoclonal immunoglobulin in, and consequent injury to, the kidneys. The diagnosis of this form of MGRS is made based on the presence of: 1) a disorder meeting the criteria for MGUS; b) decreased kidney function as evidence by, e.g. a Glomerular filtration rate of <40; and c) biopsy confirmed or suspicion of cast nephropathy, glomerulonephritis, of other morphological expressions of clonal immunoglobulin-induced kidney injury. Increased excretion of a urinary monoclonal light chain (typically >0.5 gram/day), which suggests the presence of a particularly severe form of kidney injury (myeloma cast nephropathy), supports but is not a requirement for the diagnosis of MGRS. The disorder can also be caused by a monoclonal immunoglobulin that acts as an autoantibody that activates the blood complement system to cause complement-related kidney injury. This form of MGRS is usually associated with other syndromes like glomerulopathy associated with a monoclonal immunoglobulin or C4 dense deposit disease associated with a monoclonal immunoglobulin. Diagnosis depends or identifying these other syndromes and the identification of complement components on kidney biopsy.
Regardless of the exact pathophysiology causing monoclonal immunoglobulin-induced kidney injury, MGRS has a greater morbidity and mortality than other forms of MGUS. Since renal dysfunction usually improves with therapy directed at the underlying plasma cell dyscrasia, MGRS may warrant treatment even when other parameters of plasma cell dyscrasia severity (e.g. low levels of serum monoclonal immunoglobulin and bone marrow plasma cells) suggest the presence of minimal, non-malignant disease.

Smoldering multiple myeloma stage
Smoldering multiple myeloma or SMM (also termed smoldering myeloma) is the next stage following MGUS in the spectrum of plasma cell dyscrasias. While still considered a pre-malignant condition, its chances of progressing to a malignant plasma cell dyscrasia are generally greater than that for MGUS. SMM consists of the following subtypes which represent progression of their corresponding MGUS subtypes.

Non-IgM SMM
Non-IgM SMM (also termed IgG and IgA SMM because of the rarity of IgD and IgE SMM) is diagnosed in asymptomatic individuals based on criteria identical to those listed above for Non-IgM MGUS except that: their intact IgG or IgA myeloma protein levels are equal to or greater than 30 grams/liter rather than 15 grams/liter; their bone marrow shows plasma cells comprise between 10% and <60% rather than <10% of nucleated cells; and/or their 24-hour urine contains 0.5 gram or greater levels of Bence Jones, i.e. light chain myeloma, proteins. individuals must also lack evidence of more recently established multiple myeloma-defining criteria viz., CRAB features, amyloidosis, more than one solitary plasmacytoma, and/or serum or urine free light chain κ to λ or λ to κ ratios of 100 or greater.Overall, the risk of Non-IgM SMM progressing to multiple myeloma is 10% per year for the first 5 years but falls off sharply to 3% per year for the next 5 years and thereafter to 1% per year.

Smoldering Waldenström macroglobulinemia
Smoldering Waldenström macroglobulinemia is diagnosed in asymptomatic individuals that have a serum IgM level 30 gram/liter and/or a bone marrow lymphoplasmacytoid cell infiltrate >10% of total nucleated cells. These cases should have no symptoms or findings of end organ dysfunction attributed to Waldenström macroglobulinemia such as anemia, decreases in any white blood cell count, cold agglutinin disease, hyperviscosity of blood, lymphadenopathy, hepatomegaly, splenomegaly, peripheral neuropathy, cryoglobulinemia, or constitutional symptoms.As determined by a Mayo Clinic study of 48 individuals, smoldering Waldenström macroglobulinemias risk of progression to Waldenström macroglobulinemia is estimated to be ~12% per year and then falling of sharply for at least the next 5 years to 2% per year. In this study the only factor predictive of a more rapid progress was a finding of anemia (hemoglobin level <115 grams/liter). During a 15-year follow-up, the Clinic subsequently reported that patients progressed to Waldenström macroglobulinemia, amyloidosis, or a related IgM-associated neoplasm at a rate of 6%, 39%, 59%, and 68% after the first, third, fifth, and tenth year, respectively. However, the Southwest Oncology Group in a study on 231 individuals reported that the smoldering disease progressed to overt Waldenström macroglobulinemia over 9 years in only 26% of cases.

Light chain SMM
Light chain smoldering multiple myeloma (light chain SMM) was previously termed idiopathic Bence Jones proteinuria. The condition is currently diagnosed in asymptomatic individuals who have a 24-hour urinary Bence Jones, i.e. light chain myeloma protein level, that is >0.5 grams and/or bone marrow plasma cells that are 10% to <60% of nucleated cells. These individuals must also; lack detectable IgG, IgA, IgD, IgE, or IgM myeloma proteins in sera; have a free κ/λ or λ/κ light chain ratio outside of 0.26 to 1.65 range but less than 100; and/or have no evidence for the presence of any one of the CRAB criteria, amyloidosis, or end organ damage attributable to the myeloma proteins or plasma cells.In a Mayo clinic study of 101 individuals with light chain SMM, the cumulative probability of progression to active multiple myeloma or light-chain amyloidosis in patients with light-chain SMM was 28%, 45%, and 56% after 5, 10, and 15 years, respectively. The major risk factors for progression were the level of urinary excretion of M protein, percentage of bone marrow plasma cells, and immunoparesis (i.e. reduced serum levels of intact immunoglobulins).

Paraneoplastic complications
Serious and potentially life-threatening paraneoplastic complications can occur in plasma cell dyscrasias regardless of tumor cell burden, myeloma protein levels, or the presence of other criteria suggesting the dyscrasia has entered a malignant phase. Many of these complications are caused by the tissue-destructive effects of the myeloma proteins, are predictive of a rapidly progressive disease, and require chemotherapeutic or other treatments directed at lowering the burden of the myeloma protein-producing cells. The serious paraneoplasitic diseases that complicate the plasma cell dyscrasias and may require such treatments include the following.

Amyloidosis
Amyloidosis is a general term for a protein misfolding syndrome that involves the deposition of a low molecular weight beta-pleated sheet-containing protein in extracellular tissues. These proteins normally circulate in the blood but may undergo conformational changes that cause them to auto-aggregate along their beta-pleated sheets to become insoluble and form fibril deposits in and outside of the circulation. These deposits disrupt tissue architecture and, in the case of light chains, directly injure cells, thereby causing potentially cataclysmic organ failures. There are 31 types of circulating proteins that can become misfolded and lead to distinctly different types of amyloidosis; among these, myeloma proteins, particularly free light chains, are the predominant cause of the disease. Increases in the levels of free κ or λ light chains are a common feature of plasma cell dyscrasias. These increases occur in: 40% of IgM MGUS, IgM SMM, and Waldenstroms macroglbulonemia cases; 60% to 70% of non-secretory multiple myelom cases;  90% to 95% of intact immunoglobulin multiple myeloma cases; and, by definition, 100% of light chain multiple myeloma cases. There are two different types of plasma cell dyscrasia-associated amyloidosis syndromes: amyloid light chain amyloidosis (AL amyloidosis) in which amyloid deposits consist of free light chains and amyloid heavy chain amyloidosis (AH amyloidosis) in which amyloid deposits contain only free heavy chains. The deposits in a third type, AHL amyloidosis, consists of both free light chains and free heavy chains. AHL amyloidosis is here, as in some recent reports, grouped with AH amyloidosis.

AL Amyloidosis
AL amyloidosis can occur at any stage in the plasma cell dyscrasia spectrum. Typically, patients developing this type of amyloidosis have had excess κ or λ free light chains in their urine for years before diagnosis. At diagnosis, however, they typically have a relatively small plasma cell burden (bone marrow plasma cells <5% to 7% of total nucleated cells) and in only <5% to 10% of cases do other findings indicate the presence of a malignant condition (i.e. definitive signs of multiple myeloma, Waldenström macroglobulinemia, or chronic lymphocytic leukemia associated with over-production of a clonal light chain). Nonetheless, these individuals often evidence serious involvement of the kidney (proteinuria, nephrotic syndrome) or heart (restrictive cardiomyopathy, arrhythmias) in 70% or 60% of cases, respectively, and of dysfunction in the peripheral nervous system (numbness, paresthesias) or autonomic nervous system (orthostatic hypotension) in 20% or 15% of cases, respectively. They may also exhibit evidence of liver involvement (liver failure, increases in circulating liver enzymes, bleeding due to factor X deficiency), gastrointestinal track deficiencies (malabsorption), and amyloid deposition in surface tissues (macroglossia, shoulder pad masses, cutaneous nodules). Arthritis in multiple joints, often manifested before diagnosis, is also a common feature of AL amyloidosis and has led to initial misdiagnoses of rheumatoid arthritis. Diagnosis of the disease requires evidence of increased levels of a κ or λ myeloma protein in blood and/or blood, presence of an amyloid-related organ-involvement syndrome, detection in tissues of amyloid deposition based on birefringence-staining with Congo red, and detection in tissues of κ or λ deposition based on electron microscopy or mass spectrometry. Reflecting the widespread systemic nature of the disease, patient median survival is only 8 months dating from the time of diagnosis. Treatment commonly improves this poor survival. In a Mayo Clinic study, for example, AL amyloidosis assigned stage 1, 2, 3, or 4 based on the presence of 0, 1, 2, or 3 prognostic signs (high blood levels of [cardiac troponin T]), blood levels of a marker for congestive heart failure (viz., NT-ProBNP), or free light chain ratios) had median survivals of 94.1, 40.3, 14, and 5.8 months respectively. Additional factors indicating a worse prognosis include the involvement of multiple organs, ≥ 10% bone marrow plasma cells, presence of a translocation between chromosomes 11 and 14 [i.e. t(11;14)], and chromosomal trisomy.

AH Amyloidosis
AH and AHL amyloidosis are extremely rare forms of systemic amyloidosis in which the amyloid deposit is a free heavy chain (AH amyloidosis) or a free heavy chain plus free light chain (AHL amyloidosis). Case reports have detected amyloid deposits containing a free γ, α, or μ heavy chain (or portions of one of these chains) accompanied in many cases by a free κ or λ light chain in primarily in the kidney but also the spleen and other tissues. AH plus AHL amyloidosis cases are ~17-fold less common than AL amyloidosis cases. The disease often presents late in its course with signs and/or symptoms of kidney failure such as those associated with the nephrotic syndrome and is therefore treated as a malignant condition. In a small study of 16 patients with renal amyloidosis, the 5 patients with AH amyloidosis and the 11 patients with AHL amyloidosis had less frequent concurrent cardiac involvement and better overall survival than 202 patients with renal AL amyloidosis. The hematological response to chemotherapy of the AH and AHL renal amyloidosis patients was comparable to those with renal AL amyloidosis.

POEMS syndrome
POEMS syndrome (also known as Crow–Fukase syndrome, Takatsuki disease, or PEP syndrome) is a rare and complex medical syndrome that involves a combination of syndrome-defining signs and symptoms due to the dysfunction of multiple organs. The syndrome is associated with a plasma cell dyscrasia in almost 100% of cases, pathological overexpression of certain cytokines in >95% of cases, and the lymphoproliferative disorder termed Castlemans disease in ~15% of cases. (Rare cases of POEMS have been associated with polyclonal rather than clonal plasma cells; these cases are not plasma cell dyscrasias but rather appear to be caused by the over-activity of non-malignant immune cell responses in chronic infections or autoimmune diseases.)  POEMS is an acronym standing for the characteristic signs or symptoms of the syndrome: Polyneuropathy, Organomegaly, Endocrinopathy, Plasma cell disorder (typically, the plasma cell burden is low in POEMS patients), and Skin changes (e.g. hemangioma, hyperpigmentation). The syndrome is defined by the presence of; both of two major criteria, peripheral neuropathy and a clonal plasma cell dyscrasia (increased bone marrow plasma cells in ~67% of cases; ≥1 plasmacytoma in ~33% of cases); at least one other major criteria (Castlemans disease, sclerotic bone lesions, elevated serum levels of the cytokine VEGF); and at least one minor criterion (organomegaly, extravascular volume overload [e.g. ascites, edema, pleural effusion, and/or pericardial effusion], endocrinopathy [i.e. hypogonadism, defects in the hypothalamic–pituitary–adrenal axis], skin changes, papilledema, and/or hematological manifestations [i.e. thrombocytosis or polycythemia]). The monoclonal protein in POEMS patients is typically identified as IgA or IgG which in >95% of cases contains a λ chain that is restricted to either of two members of the V lambda 1 subfamily viz., IGLV1-40*01 and IGLV1-44*01 (there are 29 other members in the V lambda family). That is, the myeloma protein in POEMS is almost invariably a clonal λ light chain variant. Deletion of chromosome 13 and chromosomal translocations but not increases in chromosome number have also been reported to occur in POEMS patients.Patients with 1 or 2 isolated plasmacytomas have been successfully treated with targeted radiotherapy to obtain relief of symptoms and sometimes complete remission of disease. (Isolated plasmacytomas may regress spontaneously.) Patients with >2 plasmacytomas or symptomatic disseminated disease have been treated with chemotherapy often followed by autologous stem-cell transplantation; these treatments have been found to reduce symptoms of the disease and lead to long-term partial remissions of disease.
The overall survival of POEMS patients who have been treated for their disease is relatively good for a disease occurring in patients with an average age of 50 years; one estimate of median overall survival is 14 years. POEMS patients evaluated to be in low and intermediate risk groups had ≥>85% survival at 10 years; those in the high risk group had a 40% survival over this time period.

Cryoglobulinemia
Cryoglobulins are proteins, principally immunoglobulins, that circulate in the blood, precipitate at temperatures <37 °C (98.6 °F), and re-solubilize upon restoring physiological blood temperatures. They are made and secreted into the blood as a result of underlying pathological conditions viz., inflammation, infection, or malignancies. Rarely, cryoglobulinemia (i.e. essential cryoglobulinemia) occurs in patients without these or other identifiable conditions. Non-essential cryoglobulonemia is classified into three types. Type 1 cryoglobulinemia (10-25% of cases) involves a circulating myeloma protein, typically IgM or IgG but in rare case reports IgA. The condition is associated with Waldenström macroglobulinemia or multiple myeloma in ~40% of type I cases, the MGUS or smoldering predecessors to these diseases in ~44% of type I cases, and other B cell lymphoproliferative disorders in ~16% of type I cases. Type II cryglobulinemia (50-60% of cases) involves circulating IgM myeloma protein with rheumatoid factor activity and therefore bound to polyclonal IgG and protein components of the blood complement system; hepatitis C virus and, far more rarely, hepatitis B virus or human immunodeficiency virus infections are the major causes of this cryoglobulinemia. Type III cryoglobulinemia (15-30% of cases) involves circulating polyclonal IgM protein with rheumatoid factor activity bound to polyclonal IgG and blood complement components; autoimmune diseases and, less commonly, hepatitis virus C infection or lymphoproliferative disorders are the cause of this type of croglobulinemia. Only types I and II are defined as plasma cell dyscrasias.Patients suffering type 1 cryoglobulinemia present with symptoms due to cold temperature-induce blood hyperviscosity and consequential interruptions of blood flow, e.g. skin lesions (lower extremity purpuric spots and papules, acrocyanosis, necrosis skin ulcers, livedo reticularis urticaria), peripheral neuropathy, blurred vision, loss of vision, hearing loss, headaches, confusion, transient ischemic attacks, chest pain, heart failure, glomerulonephritis, kidney failure, oral bleeding, and nasal bleeding. Rarely, patients may present with catastrophic decreases in blood flow to vital tissues and require emergency treatment. Symptomatic patients typically exhibit levels of a myeloma protein >5 gram/liter and can be diagnosed by simple observing the temperature-induced, reversible induction of serum precipitate formation. Patients, particularly those with catastrophic presentations, are treated with plasma exchange and/or plasmapharesis to reduce the load of circulating myeloma proteins and relieve acute symptoms. Patients with an overt malignancy are treated with the chemotherapy regimens used for Waldenstroms macroglobulinemia or multiply myeloma; patients with MGUS precursors to these diseases appear less responsive to these chemotherapeutic regimens. These patients as well as patients with overt malignancy may be treated with rituximab (kills normal and malignant B cells that bear the CD20 antigen or the proteasome inhibitor, Bortezomib.Patients suffering type II (or type III) cryoglobulinemia present with many of the symptoms of type I disease plus those of inflammatory vasculitis. Their treatments are tailored to the underlying infectious, autoimmune, or malignant disease. Type II patients associated with a monoclonal antibody and clonal plasma cells or other types of clonal B cells, are typically treated with regimens used for Walsdenstorms macroglobulonemia or multiple myeloma.

Malignant stage
In the malignant stage of plasma cell dyscrasias, a clearly excessive tumor cell burden causes symptoms and findings predictive of rapid, life-threatening progression of disease. These dyscrasias fall into several distinct categories.

Solitary plasmacytoma
Solitary plasmacytoma is an early stage malignancy with a clinical course that lies between MGUS and multiple myeloma in the spectrum of plasma cell dyscrasias. Solitary plasmacytomas typically present with local symptoms due to the growing mass of plasma cells such as the bone pain or pathologic bone fractures occurring in solitary plasmacytomas of bone or the headache, focal neurological deficits, and cranial nerve palsies occurring in extramedullary plasmacytomas of sellar and parasellar compartments of the brain. Its diagnoses must meet all four of the following criteria: biopsy-proven tumor consisting of clonal plasma cells; no evidence of any other plasmacytomas based on bone survey and MRI (or in place of MRI, CT scan); normal bone marrow examination; and absence end organ damage, CRAB features, or other signs or symptoms of systemic disease attributable to a plasma cell dyscrasia. Blood or urine myeloma proteins are usually undetectable or low in solitary plasmacytomas. Solitary plasmacytoma is a rare disease with an incidence in the USA of <450 cases per year. In a review of 1,691 cases in the US, the median age at diagnosis was 63 with males representing ~60% of all cases. The most common site of plasmacytoma involvement was bone (~58%) followed by upper or lower airway tract (~16%), soft tissue or connective tissue (~5%), central nervous system (~3%), gastrointestinal tract (~3%), skin (~1%), and all other sites (~3%). Overall median survival was 8.12 years with survival decreasing with age from 12.4 years for patients <40 to 5.2 years for patients of 60 years or older. Risk of its recurrence or progression to overt multiple myeloma within 3 years is ~10%.A subset of solitary plasmacytomas, termed solitary plasmacytoma with minimal bone marrow involvement, has the same criteria for diagnosis as solitary plasmacytoma except that bone marrow examination shows an increase in plasma cells from a normal value of ~0% to 1.5% to >~1.6% but less than 10% of total nucleated cells. While its presentations and findings are similar to solitary plasmacytoma, solitary plasmacytoma with minimal bone marrow involvement is more likely to progress, i.e. it recurs or becomes overt multiple myeloma in 20% to 60% of cases within 3 years. Solitary plasmacytomas associated with 10% or more plasma cells are diagnosed as overt multiple myeloma.

Non-secretory multiple myeloma
Non-secretory multiple myeloma represents a class of plasma cell dyscrasias where no myeloma protein is detected in serum or urine of patients with evidence of increased clonal bone marrow plasma cells and/or multiple plasmacytomas, particularly of the bone but also of soft tissues. While a pre-malignant phase is likely, most new cases of non-secretory multiple myeloma are brought to attention not because of incidental M protein detection which by definition is absent but because of patient symptoms indicative of malignancy possibly of plasma cell origin. The condition has been diagnosed based on biopsy-proved clonal plasma cell tumors and/or the presence in bone marrow of plasma cells at ≥10% of nucleated cells in individuals who have evidence of end organ damage attributable to an underlying plasma cell disorder. These patients typically also show one or more CRAB signs and lack evidence of a myeloma protein as measured by protein electrophoresis and immunofixation. However, more sensitive methods of detecting urinary and serum light chain myeloma proteins using enzyme-linked immunosorbent assays indicate that >60% of cases initially diagnosed as non-secretory multiple myeloma had abnormal levels of either a clonal κ or λ light chain in their urine or serum and therefore were better diagnosed as having light chain multiple myeloma. Based on the latter definition, non-secretory multiple myeloma represents ~1% of all multiple myeloma cases with formerly diagnosed non-secretory myelomas considered to be cases primarily of light chain multiple myeloma but on occasion "false non-secretors", i.e. cases in which there is evidence of myeloma protein secretion such as renal myeloma protein deposits.A Mayo Clinic study of 124 patients initially diagnosed as having non-secretory multiple myeloma were later found to be composed of 65% free light chain secretors and 35% true non-secretors. As a group, these patients response to therapy, time to disease recurrence, and overall survival were similar to typical myeloma patients. However, in a subset of patients diagnosed after 2001 and therefore treated with more effective therapy that included autologous stem-cell transplantation, prognosis was significantly better in non-secretory multiple myeloma patients (median survival 8.3 years) compared to typical myeloma patients (median survival 5.4 years). In addition, non-secretory patients exhibited a better prognosis than light chain-secretory patients.

Plasma Cell Myeloma with concomitant chronic Lymphocytic Leukemia/monoclonal B-Cell Lymphocytosis
Multiple myeloma occurring concurrently with chronic Lymphocytic Leukemia or its pre-malignant precursor, monoclonal B-cell lymphocytosis, is an extremely rare condition in which patients evidence findings of the  plasma cell dyscrasia plus either one of the cited clonal lymphocytic diseases. Patients are typically elderly (median age of 74, range 42–91 years old) males (51 of 66 case reports) and commonly present with a combination of symptoms related to chronic lymphocytic leukemia symptoms (fatigue, autoimmune hemolytic anemia, enlargements of liver and/or spleen and lymphadenopathy) plus symptoms of multiple myelomas. Patients exhibit two distinct populations of clonal cells in their bone marrow, blood, and/or other tissues: plasma cells, which may have an immature plasmablastic morphology and small lymphocytes, which have a morphology typical of chronic lymphocytic leukemia cells. Patients blood and/or urine evidences a plasma cell-derived myeloma proteins, either IgG, IgA, or free light chain in ~50%, 20%, and 20% of cases, respectively, but may also have a second myeloma protein made by the lymphocytic cells, either an IgM or IgG. Signs and symptoms of chronic lymphocytic leukemia commonly precede those of multiple myeloma, sometimes by years. The relationship between the two clones of cells in this combined disease has not been established although one study suggests that the clonal plasma cells and clonal lymphocytes arise from a common hematological stem cell. In general, patients with plasma cell myeloma with concomitant chronic Lymphocytic Leukemia/monoclonal B-cell Lymphocytosis have been treated with the same regimens used for multiple myeloma patients unless significant complications related to the lymphocytic component of their disease (e.g. autoimmune hemolytic anemia) require treatments used in chronic lymphocytic leukemia. Some patients who lack appreciable symptoms have been followed with no specific treatment of their disease.

Waldenström macroglobulinemia
According to the International Workshop on Waldenströms Macroglobulinemia, the disease is diagnosed in patients that have a serum IgM monoclonal protein and a bone marrow that contains ≥10% of its nucleated cells as lymphoplasmacytic cells. There is no requirement for symptomatic disease, a particular level of IgM protein, or presence of extramedullary (i.e. non-bone) lymphoplasmacytic cell infiltrates. The overall survival for this malignancy at 5 and 10 years among >5,000 patients is 62% and 39%, respectively, with newer treatment regimens anticipated to improve these survival rates in the future.

Multiple myeloma
Multiple myeloma is diagnosed in patients that (except for non-secretory multiple myeloma patients) have a clonal IgG, IgA, IgD, or IgE myeloma protein in their serum and/or a clonal κ or λ light chain in their serum or urine plus either one of two sets of criteria. In the first criteria set, patients must have ≥10% bone marrow clonal plasma cells plus ≥1 of the CRAB criteria; in the second criteria set, patients must have ≥10 bone marrow clonal plasma cells plus ≥1 of the following findings, ≥60% bone marrow clonal plasma cells, a free κ/λ or λ/κ light chain ratio in serum of ≥100 (the involved clonal light chain concentration must be ≥100 milligrams/liter), and/or >1 focal bone lesion on magnetic resonance imaging. The 5 year medium survival of patients with multiple myeloma treated with currently used treatment regiments is 48.5%.

Light chain multiple myeloma
Light chain multiple myeloma is diagnosed in patients who have: a) the criteria for diagnosis of multiple myeloma except having a serum free light chain ratio outside the normal range of 0.26 to 1.65 without evidence of an intact immunoglobulin or free heavy chain; or b) an extreme free light chain ratio, i.e. outside the range of 0.02 to 100 (with the light chain having the lower concentration being present at >10 milligrams/liter) regardless of the stage of their plasma cell dyscrasia. At the time of diagnosis, 30% to 50% of light chain multiple myeloma patients have severe renal dysfunction or kidney failure due to light chain myeloma cast nephropathy or the nephrotoxic effects of free light chains on renal tubular cells. Patients are treated similarly to patients suffering the counterparts those with multiple myeloma except that the focus is treating or preventing kidney damage using chemotherapy to reduce production of the monoclonal light chain and thereby stopping, reversing, or preventing kidney injury.

Plasma cell leukemia
Plasma cell leukemia is a form of multiple myeloma in which significant numbers of typically immature appearing plasma cells, i.e. plasmablasts, circulate in the blood. Very small numbers of plasma cells may reach the circulation in non-IgM multiple myeloma, non-IgM SMM, and, exceptionally, non-IgM MGUS. In these plasma cell dyscrasias, the presence of even very small numbers of circulating plasma cells is a poor prognostic indicator. In plasma cell leukemia, however, circulating plasma cells reach far higher numbers and at these circulating levels are associated with exceptionally poor  survival rates. The International Myeloma Working Group has defined the diagnostic criteria for plasma cell leukemia as the presence in blood of >2x109 plasma cells per liter or, alternatively, >20% of nucleated blood cells being plasma cells. More recently, the Group has suggested that values of 0.5x109 or 5%, respectively, may be more appropriate from a therapeutic viewpoint and therefore should be studied as a definitive criterion for the disease. A recent study supported this suggestion in finding that multiple myeloma patients with >5% circulating plasma cells had a prognosis much worse than that for multiple myeloma and similar to that for plasma cell leukemia. Flow cytometry immunophenotyping of blood cells to detect clonal phenotypes of plasma cells seen in multiple myeloma (e.g. the CD138+, CD38+, CD19−, CD4+/- phenotype) may be a more sensitive method to enumerate circulating clonal plasma cells and diagnose plasma cell leukemia.There are two forms of plasma cell leukemia: Primary plasma cell leukemia in which patients without a history of multiple myeloma present with diagnostically high levels of circulating plasma cells and Secondary plasma cell leukemia in which patients with multiple myeloma suffer their dyscrasias progression by the expansion of large numbers of their malignant plasma cells into the circulation and distant tissues. Historically, primary plasma cell leukemia was more common than the secondary form but with the increased survival of multiple myeloma patients due to new treatment regiments, more cases of secondary plasma cell leukemia are occurring; currently, the two forms occur in approximately equal numbers. Patients with primary plasma cell leukemia present with clinical findings that are less commonly found in multiple myeloma, e.g.  they often have hepatomegaly, splenomegaly, lymphadenopathy, nerve and central nervous system defects, bleeding tendencies secondary to thrombocytopenia, and pleural effusions. They are less likely than multiple myeloma patients to have lytic bone lesions. In several studies of patients with either form of plasma cell leukemia, the disease was associated with clonal IgG in 28% to 56% of cases, IgA in 4% to 7% of cases, and a light chain in 23% to 44% of cases; 0-12% of patients had no myeloma protein. Medium survival for primary and secondary plasma cell dyscrasias have been 7–13 months and 2–7 months, respectively, but appear to be improving with new treatment regimens.

Heavy chain disease
The four heavy chain diseases are exceedingly rare conditions associated with the production, circulation in blood, and often presence in urine of  a free clonal heavy chain with no detected clonal light chains. The heavy chain is non-functional and altered by having deletions, insertions, and point mutations due to somatic mutations in their respective coding genes. Beyond this commonality, however, these diseases have very different clinical differences. Furthermore, each of the heavy chain diseases appears to be due to rare variants of lymphoma and therefore is sometimes regarded as a B cell dyscrasia However, heavy chain diseases are still often classified with plasma cell dyscrasias. The heavy chain diseases are classified as α, γ, and μ heavy chain diseases and are based respectively on >400, 130, and 30-40 case reports as reviewed in a 2014 publication.

α Heavy chain disease
α Heavy chain disease (also termed immunoproliferative small intestinal disease or IPSID, Mediterranean lymphoma, and Seligmann disease) afflicts primarily individuals of  Mediterranean, North African, and Middle Eastern descent of lower economic status. Many cases are centered in the Middle East and associated with relatively unsanitary living conditions. The disease usually appears between the ages 10 and 30 and in some cases may be an aberrant immune response to a parasite or other microorganism. The disease commonly effects the gastrointestinal tract leading to signs and symptoms of a malabsorption syndrome or, far less commonly, the respiratory tract with signs and symptoms of respiratory dysfunction. Involved tissues usually include mucosa-associated lymphoid tissues and evidence a histology of lymphoplasmacytoid infiltrates accompanied by large numbers of plasma cells and small lymphocytes. The plasma cells therein express the monoclonal α chain and therefore are clonal in nature and the sole or contributing producer of the α chain myeloma protein. Some 57% to 66% of patients present with disseminated lymphoma, 17% to 36% of patients present with a localized lymphoma, and 9% to 17% of patients lack any evidence of a lymphoplasmacytic neoplasm. A majority of the latter patients have an autoimmune disease or a chronic infection which may be responsible for, or contribute to, production of the α heavy chain. Studies indicated that a sub-set particularly of the digestive form of heavy chain disease is caused by infection. This is based on findings that the majority of α heavy chain disease patients are in the lower economic class living under unsanitary conditions, that gastrointestinal bacterial and parasitic infections have been documented in many of these patients, and that long-term (>6 months) appropriately selected antibiotic therapy has improved the condition in 33% to 71% of patients who are at an early stage of the disease and documented to be infected. However, these patients frequently relapse. Patients resistant to antibiotic trials have been treated with multiple drug chemotherapy to obtain complete remission rates of 64% and an overall 5 year survival of 67%.

γ heavy chain disease
γ Heavy chain disease (also termed Franklin disease or Franklins disease) presents in three patterns: a) aggressive lymphoma (57% to 66% of cases) associated with constitutional symptoms and in 50% of cases with enlargement of lymph nodes, spleen, and/or liver; b) localized lymphoma (~25% of cases) with lymphoma limited to the bone marrow or an extra-nodal site, usually the skin but sometimes the thyroid gland, parotid gland, oropharyngeal cavity, conjunctiva, or gastrointestinal tract; and c) no lymphoma (9% to 17% of cases) associated typically with a preexistent autoimmune disease but no evidence of lymphoma. Involved lymphoma-infiltrated tissues typically show a mixture of lymphoplamsmacytoid cells, plasma cells, lymphocytes, and sometimes variable numbers of eosinophils and hystiocytes. Treatment of the disease varies with its clinical severity </s>


<s> [INST] <<SYS>> You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information. <</SYS>> What is Hemotympanum and explain in detail? [/INST] Hemotympanum, or hematotympanum, refers to the presence of blood in the tympanic cavity of the middle ear. Hemotympanum is often the result of basilar skull fracture.Hemotympanum refers to the presence of blood in the middle ear, which is the area behind the eardrum. In most cases, the blood is trapped behind the eardrum, so no discharge is visible.
Treating hemotympanum depends on the underlying cause.

Presentation
The most common symptoms of hemotympanum are:

pain
sense of fullness in the ear
hearing loss

Causes
Skull fracture
A basal skull fracture is a fracture in one of the bones at the base of the skull. This is almost always caused by impact trauma such as a hard fall or a car crash. If the temporal bone is affected, one of the following may co-occur:

Auricular cerebrospinal fluid discharge
Dizziness
Bruises around the eyes or behind the ears
Facial weakness
Difficulty seeing, smelling, or hearing

Nasal packing
Following nasal surgery or frequent nosebleeds, gauze or cotton may be inserted into the nose to stop the bleeding </s>


<s> [INST] <<SYS>> You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information. <</SYS>> What is Chondrodermatitis nodularis chronica helicis and explain in detail? [/INST]  </s>


<s> [INST] <<SYS>> You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information. <</SYS>> What is Phenylketonuria and explain in detail? [/INST] Phenylketonuria (PKU) is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine. Untreated PKU can lead to intellectual disability, seizures, behavioral problems, and mental disorders. It may also result in a musty smell and lighter skin. A baby born to a mother who has poorly treated PKU may have heart problems, a small head, and low birth weight.Phenylketonuria is a genetic disorder inherited from a persons parents. It is due to mutations in the PAH gene, which results in low levels of the enzyme phenylalanine hydroxylase. This results in the buildup of dietary phenylalanine to potentially toxic levels. It is autosomal recessive, meaning that both copies of the gene must be mutated for the condition to develop. There are two main types, classic PKU and variant PKU, depending on whether any enzyme function remains. Those with one copy of a mutated gene typically do not have symptoms. Many countries have newborn screening programs for the disease.Treatment is with a diet that (1) is low in foods that contain phenylalanine, and which (2) includes special supplements. Babies should use a special formula with a small amount of breast milk. The diet should begin as soon as possible after birth and be continued for life. People who are diagnosed early and maintain a strict diet can have normal health and a normal life span. Effectiveness is monitored through periodic blood tests. The medication sapropterin dihydrochloride may be useful in some.Phenylketonuria affects about 1 in 12,000 babies. Males and females are affected equally. The disease was discovered in 1934 by Ivar Asbjørn Følling, with the importance of diet determined in 1935. Gene therapy, while promising, requires a great deal more study as of 2014.

Signs and symptoms
Untreated PKU can lead to intellectual disability, seizures, behavioral problems, and mental disorders. It may also result in a musty smell and lighter skin. A baby born to a mother who has poorly treated PKU may have heart problems, a small head, and low birth weight.Because the mothers body is able to break down phenylalanine during pregnancy, infants with PKU are normal at birth. The disease is not detectable by physical examination at that time, because no damage has yet been done. Newborn screening is performed to detect the disease and initiate treatment before any damage is done. The blood sample is usually taken by a heel prick, typically performed 2–7 days after birth. This test can reveal elevated phenylalanine levels after one or two days of normal infant feeding.If a child is not diagnosed during the routine newborn screening test and a phenylalanine-restricted diet is not introduced, then phenylalanine levels in the blood will increase over time. Toxic levels of phenylalanine (and insufficient levels of tyrosine) can interfere with infant development in ways that have permanent effects. The disease may present clinically with seizures,  hypopigmentation (excessively fair hair and skin), and a "musty odor" to the babys sweat and urine (due to phenylacetate, a carboxylic acid produced by the oxidation of phenylacetone). In most cases, a repeat test should be done at approximately two weeks of age to verify the initial test and uncover any phenylketonuria that was initially missed.Untreated children often fail to attain early developmental milestones, develop microcephaly, and demonstrate progressive impairment of cerebral function. Hyperactivity, EEG abnormalities, and seizures, and severe learning disabilities are major clinical problems later in life. A characteristic "musty or mousy" odor on the skin, as well as a predisposition for eczema, persist throughout life in the absence of treatment.The damage done to the brain if PKU is untreated during the first months of life is not reversible. It is critical to control the diet of infants with PKU very carefully so that the brain has an opportunity to develop normally. Affected children who are detected at birth and treated are much less likely to develop neurological problems or have seizures and intellectual disability (though such clinical disorders are still possible including asthma, eczema, anemia, weight gain, renal insufficiency, osteoporosis, gastritis, esophagus, and kidney deficiencies, kidney stones, and hypertension). Additionally, major depressive disorders occur 230% higher than controls; dizziness and giddiness occur 180% higher; chronic ischemic heart disease, asthma, diabetes, and gastroenteritis occur 170% higher; and stress and adjustment disorders occur 160% higher. In general, however, outcomes for people treated for PKU are good. Treated people may have no detectable physical, neurological, or developmental problems at all.

Genetics
PKU is an autosomal recessive metabolic genetic disorder. As an autosomal recessive disorder, two PKU alleles are required for an individual to experience symptoms of the disease. For a child to inherit PKU, both the mother and father must have and pass on the defective gene. If both parents are carriers for PKU, there is a 25% chance any child they have will be born with the disorder, a 50% chance the child will be a carrier and a 25% chance the child will neither develop nor be a carrier for the disease.PKU is characterized by homozygous or compound heterozygous mutations in the gene for the hepatic enzyme phenylalanine hydroxylase (PAH), rendering it nonfunctional.: 541  This enzyme is necessary to metabolize the amino acid phenylalanine (Phe) to the amino acid tyrosine (Tyr). When PAH activity is reduced, phenylalanine accumulates and is converted into phenylpyruvate (also known as phenylketone), which can be detected in the urine.Carriers of a single PKU allele do not exhibit symptoms of the disease but  appear to be protected to some extent against the fungal toxin ochratoxin A. This accounts for the persistence of the allele in certain populations in that it confers a selective advantage—in other words, being a heterozygote is advantageous.The PAH gene is located on chromosome 12 in the bands 12q22-q24.2. As of 2000, around 400 disease-causing mutations had been found in the PAH gene. This is an example of allelic genetic heterogeneity.

Pathophysiology
When phenylalanine (Phe) cannot be metabolized by the body, a typical diet that would be healthy for people without PKU causes abnormally high levels of Phe to accumulate in the blood, which is toxic to the brain. If left untreated (and often even in treatment), complications of PKU include severe intellectual disability, brain function abnormalities, microcephaly, mood disorders, irregular motor functioning, and behavioral problems such as attention deficit hyperactivity disorder, as well as physical symptoms such as a "musty" odor, eczema, and unusually light skin and hair coloration.

Classical PKU
Classical PKU, and its less severe forms "mild PKU" and "mild hyperphenylalaninemia" are caused by a mutated gene for the enzyme phenylalanine hydroxylase (PAH), which converts the amino acid phenylalanine ("Phe") to other essential compounds in the body, in particular tyrosine. Tyrosine is a conditionally essential amino acid for PKU patients because without PAH it cannot be produced in the body through the breakdown of phenylalanine. Tyrosine is necessary for the production of neurotransmitters like epinephrine, norepinephrine, and dopamine.PAH deficiency causes a spectrum of disorders, including classic phenylketonuria (PKU) and mild hyperphenylalaninemia (also known as "hyperphe" or "mild HPA"), a less severe accumulation of phenylalanine. Compared to classic PKU patients, patients with "hyperphe" have greater PAH enzyme activity and are able to tolerate larger amounts of phenylalanine in their diets. Without dietary intervention, mild HPA patients have blood Phe levels higher than those with normal PAH activity. There is currently no international consensus on the definition of mild HPA, however, it is most frequently diagnosed at blood Phe levels between 2–6 mg/dL.Phenylalanine is a large, neutral amino acid (LNAA). LNAAs compete for transport across the blood–brain barrier (BBB) via the large neutral amino acid transporter (LNAAT). If phenylalanine is in excess in the blood, it will saturate the transporter. Excessive levels of phenylalanine tend to decrease the levels of other LNAAs in the brain. As these amino acids are necessary for protein and neurotransmitter synthesis, Phe buildup hinders the development of the brain, causing intellectual disability.Recent research suggests that neurocognitive, psychosocial, quality of life, growth, nutrition, bone pathology are slightly suboptimal even for patients who are treated and maintain their Phe levels in the target range, if their diet is not supplemented with other amino acids.Classic PKU affects myelination and white matter tracts in untreated infants; this may be one major cause of neurological problems associated with phenylketonuria. Differences in white matter development are observable with magnetic resonance imaging. Abnormalities in gray matter can also be detected, particularly in the motor and pre-motor cortex, thalamus and the hippocampus.It was recently suggested that PKU may resemble amyloid diseases, such as Alzheimers disease and Parkinsons disease, due to the formation of toxic amyloid-like assemblies of phenylalanine.

Tetrahydrobiopterin-deficient hyperphenylalaninemia
A rarer form of hyperphenylalaninemia is tetrahydrobiopterin deficiency, which occurs when the PAH enzyme is normal, and a defect is found in the biosynthesis or recycling of the cofactor tetrahydrobiopterin (BH4). BH4 is necessary for proper activity of the enzyme PAH, and this coenzyme can be supplemented as treatment. Those with this form of hyperphenylalaninemia may have a deficiency of tyrosine (which is created from phenylalanine by PAH), in which case treatment is supplementation of tyrosine to account for this deficiency.Levels of dopamine can be used to distinguish between these two types. Tetrahydrobiopterin is required to convert Phe to Tyr and is required to convert Tyr to L-DOPA via the enzyme tyrosine hydroxylase. L-DOPA, in turn, is converted to dopamine. Low levels of dopamine lead to high levels of prolactin. By contrast, in classical PKU (without dihydrobiopterin involvement), prolactin levels would be relatively normal.As of 2020, tetrahydrobiopterin deficiency was known to result from defects in five genes.

Metabolic pathways
The enzyme phenylalanine hydroxylase normally converts the amino acid phenylalanine into the amino acid tyrosine. If this reaction does not take place, phenylalanine accumulates and tyrosine is deficient. Excessive phenylalanine can be metabolized into phenylketones through the minor route, a transaminase pathway with glutamate. Metabolites include phenylacetate, phenylpyruvate and phenethylamine. Elevated levels of phenylalanine in the blood and detection of phenylketones in the urine is diagnostic, however most patients are diagnosed via newborn screening.

Screening
PKU is commonly included in the newborn screening panel of many countries, with varied detection techniques. Most babies in developed countries are screened for PKU soon after birth.  Screening for PKU is done with bacterial inhibition assay (Guthrie test), immunoassays using fluorometric or photometric detection, or amino acid measurement using tandem mass spectrometry (MS/MS).  Measurements done using MS/MS determine the concentration of Phe and the ratio of Phe to tyrosine, the ratio will be elevated in PKU.

Treatment
PKU is not curable. However, if PKU is diagnosed early enough, an affected newborn can grow up with normal brain development by managing and controlling phenylalanine ("Phe") levels through diet, or a combination of diet and medication.

Diet
People who follow the prescribed dietary treatment from birth may (but not always) have no symptoms. Their PKU would be detectable only by a blood test. People must adhere to a special diet low in Phe for optimal brain development. Since Phe is necessary for the synthesis of many proteins, it is required for appropriate growth, but levels must be strictly controlled.
For people who do not have phenylketonuria, the U.S. Institute of Medicine set recommended at least 33 mg/kg body weight/day phenylalanine plus tyrosine for adults 19 years and older. For people with PKU, a recommendation for children up to age 10 years is 200 to 500 mg/d; for older children and adults below 600  mg/day . Where in the range depends on body weight and age, and on monitoring blood concentration.Optimal health ranges (or "target ranges") are between 120 and 360 μmol/L or equivalently 2 to 6 mg/dL. This is optimally to be achieved during at least the first 10 years, to allow the brain to develop normally.
The diet requires restricting or eliminating foods high in Phe, such as soybeans, egg whites, shrimp, chicken breast, spirulina, watercress, fish, nuts, crayfish, lobster, tuna, turkey, legumes, and lowfat cottage cheese. Starchy foods, such as potatoes and corn are generally acceptable in controlled amounts, but the quantity of Phe consumed from these foods must be monitored. A corn-free diet may be prescribed in some cases. A food diary is usually kept to record the amount of Phe consumed with each meal, snack, or drink. An "exchange" system can be used to calculate the amount of Phe in a portion of food from the protein content identified on a nutritional information label. Lower-protein "medical food" substitutes are often used in place of normal bread, pasta, and other grain-based foods, which contain a significant amount of Phe. Many fruits and vegetables are lower in Phe and can be eaten in larger quantities. Infants may still be breastfed to provide all of the benefits of breastmilk, but the quantity must also be monitored and supplementation for missing nutrients will be required.  The sweetener aspartame, present in many diet foods and soft drinks, must also be avoided, as aspartame contains phenylalanine.Different people can tolerate different amounts of Phe in their diet. Regular blood tests are used to determine the effects of dietary Phe intake on blood Phe level.

Nutritional supplements
Supplementary "protein substitute" formulas are typically prescribed for people PKU (starting in infancy) to provide the amino acids and other necessary nutrients that would otherwise be lacking in a low-phenylalanine diet. Tyrosine, which is normally derived from phenylalanine and which is necessary for normal brain function, is usually supplemented. Consumption of the protein substitute formulas can actually reduce phenylalanine levels, probably because it stops the process of  protein catabolism from releasing Phe stored in the muscles and other tissues into the blood. Many PKU patients have their highest Phe levels after a period of fasting (such as overnight) because fasting triggers catabolism. A diet that is low in phenylalanine but does not include protein substitutes may also fail to lower blood Phe levels, since a nutritionally insufficient diet may also trigger catabolism. For all these reasons, the prescription formula is an important part of the treatment for patients with classic PKU.Evidence supports dietary supplementation with large neutral amino acids (LNAAs). The LNAAs (e.g. leu, tyr, trp, met, his, ile, val, thr) may compete with phe for specific carrier proteins that transport LNAAs across the intestinal mucosa into the blood and across the blood–brain barrier into the brain. Its use is limited in the US due to the cost but is available in most countries as part of a low protein / PHE diet to replace missing nutrients.
Another interesting treatment strategy is casein glycomacropeptide (CGMP), which is a milk peptide naturally free of Phe in its pure form CGMP can substitute for the main part of the free amino acids in the PKU diet and provides several beneficial nutritional effects compared to free amino acids. The fact that CGMP is a peptide ensures that the absorption rate of its amino acids is prolonged compared to free amino acids and thereby results in improved protein retention and increased satiety compared to free amino acids. Another important benefit of CGMP is that the taste is significantly improved when CGMP substitutes part of the free amino acids and this may help ensure improved compliance to the PKU diet.
Furthermore, CGMP contains a high amount of the Phe-lowering LNAAs, which constitutes about 41 g per 100 g protein and will therefore help maintain plasma phe levels in the target range.

Enzyme substitutes
In 2018, the FDA approved an enzyme substitute called pegvaliase which metabolizes phenylalanine. It is for adults who are poorly managed on other treatments.Tetrahydrobiopterin (BH4) (a cofactor for the oxidation of phenylalanine) when taken by mouth can reduce blood levels of this amino acid in some people.

Mothers
For women with PKU, it is important for the health of their children to maintain low Phe levels before and during pregnancy. Though the developing fetus may only be a carrier of the PKU gene, the intrauterine environment can have very high levels of phenylalanine, which can cross the placenta. The child may develop congenital heart disease, growth retardation, microcephaly and intellectual disability as a result. PKU-affected women themselves are not at risk of additional complications during pregnancy.In most countries, women with PKU who wish to have children are advised to lower their blood Phe levels (typically to between 2 and 6 mg/dL) before they become pregnant, and carefully control their levels throughout the pregnancy. This is achieved by performing regular blood tests and adhering very strictly to a diet, in general monitored on a day-to-day basis by a specialist metabolic dietitian. In many cases, as the fetus liver begins to develop and produce PAH normally, the mothers blood Phe levels will drop, requiring an increased intake to remain within the safe range of 2–6 mg/dL. The mothers daily Phe intake may double or even triple by the end of the pregnancy, as a result. When maternal blood Phe levels fall below 2 mg/dL, anecdotal reports indicate that the mothers may experience adverse effects, including headaches, nausea, hair loss, and general malaise. When low phenylalanine levels are maintained for the duration of pregnancy, there are no elevated levels of risk of birth defects compared with a baby born to a non-PKU mother.

Epidemiology
The average number of new cases of PKU varies in different human populations. United States Caucasians are affected at a rate of 1 in 10,000. Turkey has the highest documented rate in the world, with 1 in 2,600 births, while countries such as Finland and Japan have extremely low rates with fewer than one case of PKU in 100,000 births. A 1987 study from Slovakia reports a Roma population with an extremely high incidence of PKU (one case in 40 births) due to extensive inbreeding. It is the most common amino acid metabolic problem in the United Kingdom.

History
Before the causes of PKU were understood, PKU caused severe disability in most people who inherited the relevant mutations. Nobel and Pulitzer Prize winning author Pearl S. Buck had a daughter named Carol who lived with PKU before treatment was available, and wrote an account of its effects in a book called The Child Who Never Grew. Many untreated PKU patients born before widespread newborn screening are still alive, largely in dependent living homes/institutions.Phenylketonuria was discovered by the Norwegian physician Ivar Asbjørn Følling in 1934 when he noticed hyperphenylalaninemia (HPA) was associated with intellectual disability. In Norway, this disorder is known as Føllings disease, named after its discoverer. Følling was one of the first physicians to apply detailed chemical analysis to the study of disease.
In 1934 at Rikshospitalet, Følling saw a young woman named Borgny Egeland. She had two children, Liv and Dag, who had been normal at birth but subsequently developed intellectual disability. When Dag was about a year old, the mother noticed a strong smell to his urine. Følling obtained urine samples from the children and, after many tests, he found that the substance causing the odor in the urine was phenylpyruvic acid. The children, he concluded, had excess phenylpyruvic acid in the urine, the condition which came to be called phenylketonuria (PKU).His careful analysis of the urine of the two affected siblings led him to request many physicians near Oslo to test the urine of other affected patients </s>


<s> [INST] <<SYS>> You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information. <</SYS>> What is Folie à deux and explain in detail? [/INST] Folie à deux (folly of two, or madness [shared] by two), also known as shared psychosis or shared delusional disorder (SDD), is a collection of rare psychiatric syndromes in which symptoms of a delusional belief, and sometimes hallucinations, are transmitted from one individual to another. The same syndrome shared by more than two people may be called folie à... trois (three) or quatre (four); and further, folie en famille (family madness) or even folie à plusieurs (madness of several).
The disorder, first conceptualized in 19th-century French psychiatry by Charles Lasègue and Jules Falret, and is also known as Lasègue–Falret syndrome.Recent psychiatric classifications refer to the syndrome as shared psychotic disorder (DSM-4 – 297.3) and induced delusional disorder (ICD-10 – F24), although the research literature largely uses the original name.
This disorder is not in the current, fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which considers the criteria to be insufficient or inadequate. DSM-5 does not consider Shared Psychotic Disorder (Folie à Deux) as a separate entity; rather, the physician should classify it as "Delusional Disorder" or in the "Other Specified Schizophrenia Spectrum and Other Psychotic Disorder".

Signs and symptoms
This syndrome is most commonly diagnosed when the two or more individuals of concern live in proximity, may be socially or physically isolated, and have little interaction with other people.
Various sub-classifications of folie à deux have been proposed to describe how the delusional belief comes to be held by more than one person:
Folie imposée
Where a dominant person (known as the primary, inducer, or principal) initially forms a delusional belief during a psychotic episode and imposes it on another person or persons (the secondary, acceptor, or associate) with the assumption that the secondary person might not have become deluded if left to his or her own devices. If the parties are admitted to hospital separately, then the delusions in the person with the induced beliefs usually resolve without the need of medication.
Folie simultanée
Either the situation where two people considered to independently experience psychosis influence the content of each others delusions so they become identical or strikingly similar, or one in which two people "morbidly predisposed" to delusional psychosis mutually trigger symptoms in each other.Folie à deux and its more populous derivatives are psychiatric curiosities. The current Diagnostic and Statistical Manual of Mental Disorders states that a person cannot be diagnosed as being delusional if the belief in question is one "ordinarily accepted by other members of the persons culture or subculture." It is not clear at what point a belief considered to be delusional escapes from the folie à... diagnostic category and becomes legitimate because of the number of people holding it. When a large number of people may come to believe obviously false and potentially distressing things based purely on hearsay, these beliefs are not considered to be clinical delusions by the psychiatric profession, and are instead labelled as mass hysteria.
As with most psychological disorders, the extent and type of delusion varies, but the non-dominant persons delusional symptoms usually resemble those of the inducer. Prior to therapeutic interventions, the inducer typically does not realize that they are causing harm, but instead believe they are helping the second person to become aware of vital or otherwise notable information.

Type of delusions
Psychology Today magazine defines delusions as "fixed beliefs that do not change, even when a person is presented with conflicting evidence." Types of delusion include:
Bizarre delusions
Those which are clearly implausible and not understood by peers within the same culture, even those with psychological disorders; for example, if one thought that all of their organs had been taken out and replaced by someone elses while they were asleep without leaving any scar and without their waking up. It would be impossible to survive such a procedure, and even surgery involving transplantation of multiple organs would leave the person with severe pain, visible scars, etc.
Non-bizarre delusions
Common among those with personality disorders and are understood by people within the same culture. For example, unsubstantiated or unverifiable claims of being followed by the FBI in unmarked cars and watched via security cameras would be classified as a non-bizarre delusion; while it would be unlikely for the average person to experience such a predicament, it is possible, and therefore understood by those around them.
Mood-congruent delusions
These correspond to a persons emotions within a given timeframe, especially during an episode of mania or depression. For example, someone with this type of delusion may believe with certainty that they will win $1 million at the casino on a specific night, despite lacking any way to see the future or influence the probability of such an event. Similarly, someone in a depressive state may feel certain that their mother will get hit by lightning the next day, again in spite of having no means of predicting or controlling future events.
Mood-neutral delusions
These are unaffected by mood, and can be bizarre or non-bizarre; the formal definition provided by Mental Health Daily is "a false belief that isnt directly related to the persons emotional state." An example would be a person who is convinced that somebody has switched bodies with their neighbor, the belief persisting irrespective of changes in emotional status.

Biopsychosocial effects
As with many psychiatric disorders, shared delusional disorder can negatively impact the psychological and social aspects of a persons wellbeing. Unresolved stress resulting from a delusional disorder will eventually contribute to or increase the risk of other negative health outcomes, such as cardiovascular disease, diabetes, obesity, immunological problems, and others. These health risks increase with the severity of the disease, especially if an affected person does not receive or comply with adequate treatment.
Persons with a delusional disorder have a significantly high risk of developing psychiatric comorbidities such as depression and anxiety. This may be attributable to a genetic pattern shared by 55% of SDD patients.Shared delusional disorder can have a profoundly negative impact on a persons quality of life. Persons diagnosed with a mental health disorder commonly experience social isolation, which is detrimental to psychological health. This is especially problematic with SDD, as social isolation contributes to the onset of the disorder; in particular, relapse is likely if returning to an isolated living situation, in which shared delusions can be reinstated.

Causes
While the exact causes of SDD are unknown, the main two contributors are stress and social isolation.People who are socially isolated together tend to become dependent on those they are with, leading to an inducers influence on those around them. Additionally, people developing shared delusional disorder do not have others reminding them that their delusions are either impossible or unlikely. As a result, treatment for shared delusional disorder includes those affected be removed from the inducer.Stress is also a factor, as it is a common factor in mental illness developing or worsening. The majority of people that develop shared delusional disorder are genetically predisposed to mental illness, but this predisposition is not enough to develop a mental disorder. However, stress can increase the risk of this disorder. When stressed, an individuals adrenal gland releases the "stress hormone" cortisol into the body, increasing the brains level of dopamine; this change can be linked to the development of a mental illness, such as a shared delusional disorder.While there is no exact cause of shared psychosis, there are several factors that are contributors depending on different cultures and communities. Taking into consideration the individuals circumstance which entails their environmental changes and relationships.

Diagnosis
Shared delusional disorder is often difficult to diagnose. Usually, the person with the condition does not seek out treatment, as they do not realize that their delusion is abnormal, as it comes from someone in a dominant position who they trust. Furthermore, since their delusion comes on gradually and grows in strength over time, their doubt is slowly weakened during this time. Shared delusional disorder is diagnosed using the DSM-5, and according to this, the patient must meet three criteria:
They must have a delusion that develops in the context of a close relationship with an individual with an already established delusion.
The delusion must be very similar or even identical to the one already established one that the primary case has.
The delusion cannot be better explained by any other psychological disorder, mood disorder with psychological features, a direct result of physiological effects of substance abuse or any general medical condition.

Related phenomena
Reports have stated that a phenomenon similar to folie à deux was induced by the military incapacitating agent BZ in the late 1960s.

Prevalence
Shared delusional disorder is most commonly found in women with slightly above-average IQs, who are isolated from their family, and who are in relationships with a dominant person who has delusions. The majority of secondary cases (people who develop the shared delusion) also meet the criteria for Dependent Personality Disorder, which is characterized by a pervasive fear that leads them to need constant reassurance, support, and guidance. Additionally, 55% of secondary cases had a relative with a psychological disorder that included delusions and, as a result, the secondary cases are usually susceptible to mental illness.

Treatment
After a person has been diagnosed, the next step is to determine the proper course of treatment. The first step is to separate the formerly healthy person from the inducer, and see if the delusion goes away or lessens over time. If this is not enough to stop the delusions, there are two possible courses of action: medication or therapy. Therapy can be provided as both personal therapy and/or family therapy.
With treatment, the delusions, and therefore the disease, will eventually lessen so much so, that it will practically disappear in most cases. However, if left untreated, it can become chronic and lead to anxiety, depression, aggressive behavior, and further social isolation. Unfortunately, there are not many statistics about the prognosis of shared delusional disorder, as it is a rare disease, and it is expected that the majority of cases go unreported; however, with treatment, the prognosis is very good.

Medication
If the separation alone is not working, antipsychotics are often prescribed for a short time to prevent the delusions. Antipsychotics are medications that reduce or relieve symptoms of psychosis such as delusions or hallucinations (seeing or hearing something that is not there). Other uses of antipsychotics include stabilizing moods for people with mood swings and mood disorders ( i.e. in bipolar patients), reducing anxiety in anxiety disorders, and lessening tics in people with Tourettes. Antipsychotics do not cure psychosis, but they do help reduce symptoms; when paired with therapy, the person with the condition has the best chance of recovering. While antipsychotics are powerful, and often effective, they do have side effects, such as inducing involuntary movements. They should only be taken if absolutely required, and under the supervision of a psychiatrist.

Therapy
The two most common forms of therapy for people with shared delusional disorder are personal and family therapy.Personal therapy is one-on-one counseling that focuses on building a relationship between the counselor and the patient, and aims to create a positive environment where the patient feels that they can speak freely and truthfully. This is advantageous, as the counselor can usually get more information out of the patient to get a better idea of how to help them. Additionally, if the patient trusts what the counselor says, disproving the delusion will be easier.Family therapy is a technique in which the entire family comes into therapy together to work on their relationships, and to find ways to eliminate the delusion within the family dynamic. For example, if someones sister is the inducer, the family will have to get involved to ensure the two stay apart, and to sort out how the family dynamic will work around that. The more support a patient has, the more likely they are to recover, especially since SDD usually occurs due to social isolation.

Notable cases
In May 2008, in the case of twin sisters Ursula and Sabina Eriksson, Ursula ran into the path of an oncoming articulated lorry, sustaining severe injuries. Sabina then immediately duplicated her twins actions by stepping into the path of an oncoming car; both sisters survived the incident with severe but non-life-threatening injuries. It was later claimed that Sabina Eriksson was a secondary sufferer of folie à deux, influenced by the presence or perceived presence of her twin sister, Ursula—the primary. Sabina later told an officer at the police station, "We say in Sweden that an accident rarely comes alone. Usually at least one more follows—maybe two." However, upon her release from hospital, Sabina behaved erratically before stabbing a man to death.
Psychiatrist Reginald Medlicott published an article about the Parker–Hulme murder case, called "Paranoia of the Exalted Type in a Setting of Folie a Deux - A Study of Two Adolescent Homicides," arguing that the intense relationship and shared fantasy world of the two teenaged friends reinforced and exacerbated the mental illness that led to the murder: "each acted on the other as a resonator, increasing the pitch of their narcissism."
Psychologists H. OConnell and P.G. Doyle believe folie à plusieurs to have been at least a partial factor in the murder of Bridget Cleary. In 1895, Michael Cleary convinced several friends and relatives that his wife, Bridget Cleary, was a changeling who had been replaced by a fairy. They assisted him in physically abusing her to "cast the fairies" out, before he ultimately burned her to death shortly afterwards.
Christine and Léa Papin were two French sisters who, as live-in maids, were convicted of murdering their employers wife and daughter in Le Mans, France on February 2, 1933.
Born in Yemen in 1963 to Barbados immigrants, June and Jennifer Gibbons were known as "the Silent Twins" for speaking solely to each other in an idioglossia derived from an idiosyncratic, sped-up Bajan Creole dialect that qualified as an example of cryptophasia. The inseparable twins had a longstanding agreement that, if one died, the other must begin to speak and live a normal life, and it was during their 11-year admission to Broadmoor Hospital — where the twins had been indefinitely placed following a series of crimes (e.g. vandalism, petty theft and arson) in 1981 — that they began to believe that it was necessary for one of them to die. Jennifer agreed it should be her, and when the twins were transferred from Broadmoor to the more open Caswell Clinic in Bridgend, Wales in 1993, Jennifer could not be roused upon arrival. She was taken to the hospital where she died soon after of acute myocarditis, or inflammation of the heart. As no drugs or poison were found in her system, her death remains a mystery. Fulfilling their pact, June proceeded to live an otherwise-normal life.
The Burari Deaths, wherein a family of 11 members was found hanging in their home in Delhi, was ruled as a case of "Shared Psychosis," led by the youngest son of the matriarch.

In popular culture
In Folie à Deux (The X-Files) Season 5, Episode 19 (1998), Mulder is taken hostage by an employee who believes his boss is turning his coworkers into zombies.
Bug (2006) is a film that depicts a couple with a shared delusion that aphids are living under their skin.
In Season 2, Episode 3 of Criminal Minds, "The Perfect Storm" (2006), Dr. Reid mentions that the rapists had this condition.
Folie à Deux (2008) is an album by American rock band Fall Out Boy
The independent film Apart (2011) depicts two lovers affected and diagnosed with induced delusional disorder, trying to uncover a mysterious and tragic past they share. In a 2011 interview, director Aaron Rottinghaus stated the film was based on research from actual case studies.
Nine Perfect Strangers shows a couple who lost one of their two children. The couple and the surviving child have shared hallucinations of the dead child.
Any Porth in a Storm: The Long-Distance Walk that Goes South (2021), a travelogue by Oscar Burton, has a chapter with the title Folie à deux, referencing meeting another person dressed identically and with the same equipment who was also walking the 1000 km South West Coast Path in England. It is suggestive of the mental decay of the protagonist which becomes evident later in the story.
The upcoming DC Comics film Joker: Folie à Deux, a sequel to Joker (2019), shares its subtitle with the disorder.
Six Feet Under Season 4, Episode 3 (2004), George mentions Folie à deux to Ruth.

See also
References
Further reading
Books
Enoch, D., and H. Ball. 2001. "Folie à deux (et Folie à plusieurs)." In Uncommon psychiatric syndromes (4th ed.). London: Arnold. ISBN 0340763884
Halgin, R., and S. Whitbourne. 2002. Abnormal Psychology: Clinical Perspectives on Psychological Disorders. McGraw-Hill. ISBN 0072817216
Hatfield, Elaine; Caccioppo, John T & Rapson, Richard L. (1994). Emotional contagion (Studies in Emotional and Social Interaction). Cambridge, UK: Cambridge University Press. ISBN 0-521-44948-0.
Ketchum, James S. 2007. Chemical Warfare: Secrets Almost Forgotten A Personal Story of Medical Testing of Army Volunteers (2nd ed.). Chembook, Inc. ISBN 1424300800; ISBN 978-1424300808.
Metzner, Ralph, ed. (1999-06-02). Ayahuasca: Human Consciousness and the Spirits of Nature. New York, NY: Thunders Mouth Press. ISBN 1-56025-160-3.

Journal articles
Wehmeier PM, Barth N, Remschmidt H (2003). "Induced delusional disorder. a review of the concept and an unusual case of folie à famille". Psychopathology. 36 (1): 37–45. doi:10.1159/000069657. PMID 12679591. S2CID 144398794.
Abu-Salha, Mohammad (1998). "Folie á Deux: Two Case Reports". Jefferson Journal of Psychiatry. 14. doi:10.29046/JJP.014.1.002.
Ghasemzadeh, M. R.; Ghadiri Vasfi, M.; Nohesara, S.; Shabani, A. (2012). "Shared Psychotic Manic Syndrome in Monozygotic Twins: A Case Report" </s>