Leptospirosis misdiagnosed as pulmonary-renal syndrome.

A case of leptospirosis complicated by diffuse alveolar hemorrhage, acute renal failure, and apparent hemoglobinuria was initially diagnosed and managed as a pulmonary-renal syndrome. However, renal biopsy findings were normal. Leptospirosis may manifest with severe lung injury characterized by diffuse alveolar hemorrhage, acute respiratory distress syndrome, and acute renal failure and be accompanied by high mortality rates. Leptospirosis should be considered in patients with features of pulmonary-renal syndrome, particularly in regions known to be endemic for leptospirosis. A history of potential exposure to Leptospira is an important diagnostic clue, and empiric antimicrobial therapy should be considered.