ANCA-associated diffuse alveolar hemorrhage due to benzylthiouracil.

Benzylthiouracil has been recently observed to be associated with antineutrophil cytoplasmic antibody-positive vasculitis, resulting in crescentic glomerulonephritis. We report an 8-year-old girl treated with benzylthiouracil for Graves's disease who developed an ANCA-positive vasculitis with pulmonary hemorrhage. She responded to corticosteroids and discontinuation of benzylthiouracil. This represents the first pediatric case of benzylthiouracil-induced diffuse alveolar hemorrhage.