Familial Mediterranean fever: FMF is an autosomal recessive disorder caused by mutations in the MEFV gene. It typically presents in childhood or adolescence with periodic attacks of acute fever and localized inflammation lasting from one to three days. Intervals between attacks vary from days to months, and onset may be precipitated by physical or emotional stress. Abdominal symptoms, pleural involvement, arthralgias and arthritis are common. Leukocytosis, accelerated ESR, and progressive amyloidosis also affect many patients. Erysipeloid erythema, when present, usually involves the lower extremities. Most patients are responsive to colchicine treatment.