Henoch-Schönlein purpura.

Henoch-Schönlein purpura (HSP) is a multisystem immunoglobulin A-mediated vasculitis with a self-limited course affecting the skin, joints, gastrointestinal tract, and kidneys. HSP occurs most often in children between the ages of 3 and 10 years, and presents classically with a unique distribution of the rash to the lower extremities and the buttocks area. For this reason, a skin biopsy in children is rarely necessary for diagnosis. However, in the very young age children and adults, the rash is not classically distributed, and therefore a skin biopsy is often needed. Although there are currently no prospective controlled studies on the treatment of the different manifestations of HSP, there are several retrospectively designed studies and other physicians' personal experiences supporting the use of steroids in patients with severe gastrointestinal, severe renal, central nervous system, and testicular involvements. Severe renal and central nervous system disease may lead to life-threatening conditions, and immunosuppressive agents and plasmapheresis may be needed. The overall prognosis in HSP is excellent, but the long-term morbidity depends on the renal and neurologic involvement. One third to one half of these patients will have one or more recurrences of symptoms, usually within 6 weeks, but may occur as late as 3 to 7 years later.