TY - CHAP M1 - Book, Section TI - Henoch-Schönlein Purpura (Iga Vasculitis) A1 - Shah, Ashish A1 - Sobolewski, Brad A1 - Mittiga, Matthew R. A2 - Knoop, Kevin J. A2 - Stack, Lawrence B. A2 - Storrow, Alan B. A2 - Thurman, R. Jason Y1 - 2021 N1 - T2 - The Atlas of Emergency Medicine, 5e AB - Henoch-Schönlein purpura (HSP) is the most common systemic vasculitis in children, with a peak incidence between ages 3 and 15 years and with 90% of patients younger than age 10. It is characterized by four main clinical manifestations. The classic exanthem of HSP begins with erythematous macules or urticaria that eventually coalesce and evolve into ecchymotic lesions and palpable purpura. The lesions are more often located on the buttocks and gravity-dependent areas (lower extremities) in ambulatory children. In nonambulatory children, the lesions can be seen on the face, trunk, and upper extremities as well. Mucosal involvement is rare; however, edema of the scalp, hands, scrotum, and periorbital tissue occurs. SN - PB - McGraw-Hill CY - New York, NY Y2 - 2024/03/28 UR - accessemergencymedicine.mhmedical.com/content.aspx?aid=1181044471 ER -