Cryopyrin-associated periodic syndrome.

CAPS is a rare autoinflammatory disease associated with mutations in the NLRP3 gene that result in overactivation of the inflammasome, increased secretion of IL-1beta and IL-18, and systemic inflammation. Genetic testing has allowed for grouping of the three, previously distinct clinical syndromes of FCAS, MWS and NOMID, into a single syndrome termed CAPS. The clinical features include urticarial rash and fever, CNS and musculoskeletal involvement, ocular disorders and progressive deafness. Onset, severity and complications (mainly retardation, seizures, destructive arthropathy and amyloidosis) depend on the specific mutation. Diagnosis is determined by genetic tests but is often delayed due to lack of awareness. In Israel, the relative abundance of other autoinflammatory disorders (FMF, Behçet's disease) may result in misdiagnosis. Treatment is based on IL-1 antagonism, which usually results in prompt clinical response and may prevent amyloidosis.