TY - CHAP M1 - Book, Section TI - IgA Vasculitis (Henoch-Schönlein Purpura) A1 - Duvuru, Geetha A1 - Stone, John H. A2 - Stone, John H. PY - 2021 T2 - Current Diagnosis & Treatment: Rheumatology, 4e AB - The sine qua non of IgA vasculitis (formerly Henoch-Schönlein purpura) is nonthrombocytopenic purpura, caused by inflammation in blood vessels of the superficial dermis.The pathologic hallmarks of IgA vasculitis are a leukocytoclastic vasculitis and deposition of immunoglobulin (Ig) A in the walls of involved blood vessels.The tetrad of purpura, arthritis, glomerulonephritis, and abdominal pain is often observed. However, all four elements are not required for the diagnosis.More than 90% of cases occur in children. The disease is self-limited most of the time, resolving within a few weeks. Adult cases are sometimes more recalcitrant.Renal insufficiency develops in less than 5% of patients with IgA vasculitis. The long-term renal prognosis depends mainly on the degree of initial damage to the kidney.IgA vasculitis can be mimicked by other forms of systemic vasculitis that are more often life-threatening. For example, antineutrophil cytoplasmic antibody (ANCA)–associated vasculitides such as granulomatosis with polyangiitis and microscopic polyangiitis may also present with purpura, arthritis, and renal inflammation. Both of these disorders have the potential for serious involvement of other organs (eg, the lungs and peripheral nerves) and carry more dire renal prognoses. SN - PB - McGraw Hill CY - New York, NY Y2 - 2024/03/29 UR - accessmedicine.mhmedical.com/content.aspx?aid=1180197690 ER -