Henoch-Schönlein purpura.

Henoch-Schönlein purpura (HSP) is the most common vasculitis syndrome of childhood. It is also known as anaphylactoid purpura, leukocytoclastic vasculitis, allergic vasculitis, and rarely, as rheumatoid purpura. It is generally a benign, self-limited disorder that follows an intercurrent illness, usually of the upper-respiratory tract. The classic triad of clinical symptoms and signs includes purpuric rash, abdominal cramping, and hematuria, but the spectrum of the clinical expression of HSP may vary from only minimal petechial rash to severe gastrointestinal, renal, neurologic, pulmonary, and joint disease. Most children have self-limited disease, and on long-term follow-up, systemic involvement or serious sequelae are not frequent. The current lack of knowledge about the factors underlying both the etiology and pathogenesis and the extent of clinical expression of HSP is illustrated in the recent literature. In addition, there is no agreement regarding the role of corticosteroids in the clinical management of HSP, and this subject has not received adequate attention during the past year. The recent clinical literature emphasizes the distinction between HSP and other hypersensitivity vasculitides and provides several in-depth reviews and multiple case reports illustrating the expanding clinical spectrum of the disorder. Exciting developments regarding immunologic aspects of HSP have been published and are summarized. The utility of antineutrophil cytoplasmic antibody as it applies to HSP remains to be elucidated.