IgA Vasculitis

IgA vasculitis, previously known as Henoch-Schonlein purpura, is an autoimmune disease that most commonly affects children and causes inflammation of small blood vessels. It produces palpable purpura, small raised patches of bleeding beneath the skin, often together with joint pain and abdominal pain, and can also affect the kidneys, causing small amounts of blood and protein to appear in the urine. It is caused by deposits of immune complexes containing the antibody immunoglobulin A in blood vessel walls, though the exact reason this happens is unknown, and the disease is often preceded by an infection such as a sore throat. In children it usually resolves within several weeks with no treatment beyond symptom control, though it relapses in about one in three cases and causes lasting kidney damage in about one in a hundred; in adults it tends to follow a relapsing and remitting course with a higher rate of complications.