musculoskeletal and connective tissue disorders
Immunoglobulin A–Associated Vasculitis (IgAV)
Introduction
Immunoglobulin A–associated vasculitis (formerly called Henoch-Schönlein purpura) is vasculitis that affects primarily small vessels. It occurs most often in children. Common manifestations include palpable purpura, arthralgias, gastrointestinal (GI) symptoms and signs, and glomerulonephritis. Diagnosis is clinical in children but usually warrants biopsy in adults. Disease is usually self-limited in children and chronic in adults. Corticosteroids can relieve arthralgias and GI symptoms but do not alter the course of the disease. Progressive glomerulonephritis may require high-dose corticosteroids andcyclophosphamide. (See also Overview of Vasculitis .) IgA-containing immune complexes are deposited in small vessels of the skin and other sites. Possible inciting antigens include viruses that cause upper respiratory infections, streptococcal infection, drugs, foods, insect bites, and immunizations. Focal, segmental proliferative glomerulonephritis is typical but usually mild. 