Pulmonary hemorrhage with hematuria: do not forget IgA nephropathy.

IgA nephropathy is the commonest cause of glomerulonephritis worldwide, and is usually a renal-limited disease. In rare cases, IgA nephropathy may also present with a pulmonary-renal syndrome in which pulmonary hemorrhage is a critical feature. Patients presenting with IgA nephropathy and pulmonary hemorrhage have high morbidity and are at high risk for mortality unless rapid immunosuppressive therapy is instituted.