Leptospirosis Presenting as Diffuse Alveolar Hemorrhage

Diffuse alveolar hemorrhage (DAH) syndrome has a mortality rate of 30 to 60%. A 15-year-old male patient presented with a seven-day abdominal pain, vomiting, non-dysenteric diarrhea, conjunctival injection, and fever. Chest radiography revealed bilateral interstitial infiltrates predominating in the lower left lobe. The patient’s condition worsened within hours, with the development of massive hemoptysis, acute respiratory dis- tress syndrome (ARDS), arterial hypotension, and hematocrit decline requiring mechanical ventilation. A chest computed tomography (CT) showed ground-glass opacities with consolidation areas in lower lobes, diffuse tree-in-bud opacities, and centrilobular nodules. A bronchoscopy was conducted without endoluminal lesions and bronchoalveolar lavage (BAL) consistent with alveolar hemorrhage. DAH was diagnosed, and the patient received therapy with intravenous methylpred- nisolone. The outcome of treatment was successful after eight days of mechanical ventilation. Leptospirosis was di- agnosed by serology after discharge. The laboratory findings were normal, and a chest CT scan showed the resolution of the infiltrates. Early recognition of severe hemorrhagic pulmonary syndrome, which has a high mortality rate, is crucial. Therefore, leptospirosis should be suspected as a differential diagnosis in every patient with alveolar hemorrhage, ARDS manifestations, and epidemiological factors.