Immunoglobulin A Vasculitis
Overview
Plain-Language Overview
Immunoglobulin A Vasculitis is a condition that causes inflammation in the small blood vessels, primarily affecting the skin, joints, intestines, and kidneys. It mainly involves the immune system producing excess IgA antibodies that deposit in blood vessel walls, leading to swelling and damage. This inflammation can cause a distinctive rash of purplish spots, joint pain, abdominal pain, and sometimes kidney problems. The condition is most common in children but can affect adults as well. It often follows an infection, such as a cold or throat infection. The main health impact comes from the blood vessel inflammation causing symptoms and potential organ involvement.
Clinical Definition
Immunoglobulin A Vasculitis (formerly Henoch-Schönlein purpura) is a systemic small-vessel vasculitis characterized by IgA1-dominant immune complex deposition in vessel walls. It is typically triggered by an abnormal immune response to infections, leading to leukocytoclastic vasculitis with palpable purpura, arthralgia, abdominal pain, and renal involvement. The pathogenesis involves IgA immune complex deposition in postcapillary venules, causing complement activation and vessel inflammation. It is the most common vasculitis in children and can cause significant morbidity due to glomerulonephritis. Diagnosis relies on clinical presentation and histopathology showing IgA deposition on immunofluorescence. The disease is usually self-limited but requires monitoring for renal complications.