Wiskott–Aldrich syndrome (WAS) is a rare X-linked recessive disease characterized by eczema, thrombocytopenia (low platelet count), immune deficiency, and bloody diarrhea (secondary to the thrombocytopenia). It is also sometimes called the eczema-thrombocytopenia-immunodeficiency syndrome in keeping with Aldrichs original description in 1954. The WAS-related disorders of X-linked thrombocytopenia (XLT) and X-linked congenital neutropenia (XLN) may present with similar but less severe symptoms and are caused by mutations of the same gene. Signs and symptoms
WAS occurs most often in males due to its X-linked recessive pattern of inheritance, affecting between 1 and 10 males per million. The first signs are usually petechiae and bruising, resulting from a low platelet count (i.e. thrombocytopenia). Spontaneous nose bleeds and bloody diarrhea are also common and eczema typically develops within the first month of life. Recurrent bacterial infections typically develop by three months of age. The majority of children with WAS develop at least one autoimmune disorder, and cancers (mainly lymphoma and leukemia) develop in up to a third of patients. Immunoglobulin M (IgM) levels are reduced, IgA and IgE are elevated, and IgG levels can be normal, reduced, or elevated. In addition to thrombocytopenia, WAS patients have abnormally small platelets (i.e. microthrombocytes) and ~30% also have elevated eosinophil  counts (i.e. eosinophilia). Pathophysiology
The microthrombocytes seen in WAS patients have only been observed in one other condition, ARPC1B deficiency. In both conditions the defective platelets are thought to be removed from circulation by the spleen and/or liver, leading to low platelet counts.
People are at increased risk of developing CSOM when they have poor eustachian tube function, a history of multiple episodes of acute otitis media, live in crowded conditions, and attend paediatric day care facilities. Those with craniofacial malformations such as cleft lip and palate, Down syndrome, and microcephaly are at higher risk.Worldwide approximately 11% of the human population is affected by AOM every year, or 709 million cases. About 4.4% of the population develop CSOM.According to the World Health Organization, CSOM is a primary cause of hearing loss in children. Adults with recurrent episodes of CSOM have a higher risk of developing permanent conductive and sensorineural hearing loss. In Britain, 0.9% of children and 0.5% of adults have CSOM, with no difference between the sexes. The incidence of CSOM across the world varies dramatically where high income countries have a relatively low prevalence while in low income countries the prevalence may be up to three times as great. Each year 21,000 people worldwide die due to complications of CSOM. Adhesive otitis media
Adhesive otitis media occurs when a thin retracted ear drum becomes sucked into the middle-ear space and stuck (i.e., adherent) to the ossicles and other bones of the middle ear. Prevention
AOM is far less common in breastfed infants than in formula-fed infants, and the greatest protection is associated with exclusive breastfeeding (no formula use) for the first six months of life.