In medicine (rheumatology and pediatrics)<unk>  <unk> , also known as allergic<unk>  is a systemic vasculitis (inflammation of blood vessels) characterized by deposition of immune complexes containing the antibody IgA, especially in the skin and kidney. It occurs mainly in children. Typical symptoms include palpable<unk>  (small hemorrhages in the skin), joint pains and abdominal pain. Most cases are self-limiting and require no treatment apart from symptom control, but the disease may relapse (in 33% of cases) and cause irreversible kidney damage (in 1%).
Henoch-Schönlein purpura
Golfer's vasculitis
Hennekam syndrome
Roussy–Lévy syndrome
Serum sickness
Hemolytic-uremic syndrome
Cold agglutinin disease
Hemorrhagic fever with renal syndrome 