Microscopic polyangiitis (MPA), previously called hypersensitivity angiitis, is a systemic necrotizing vasculitis that involves many organ systems including the skin, joints, kidneys, and lungs. Microscopic polyangiitis most commonly affects adults in the fourth and fifth decades of life, with only a few cases reported in children. We describe a pediatric patient with microscopic polyangiitis. Arch Fam Med. 2000;9:1189-1192