High-resolution computed tomography findings in a case of severe leptospira infection (Weil disease) complicated with Jarisch-Herxheimer reaction.

In this report, we describe a case of Weil disease. Chest x-ray and computed tomography (CT) findings showed temporary deterioration 1 day after the initiation of antibiotic treatment, and high-resolution CT findings with the patient's physical findings made us suspect pulmonary alveolar hemorrhage (PAH). We believed that the PAH had been induced by Weil disease and subsequently caused Jarisch-Herxheimer reaction. We confirmed the patient's contact history with mice, and symptoms improved immediately after starting appropriate treatments. Leptospirosis is a relatively rare cause of PAH. Therefore, the possibility of this disease should be included in the differential diagnosis, especially when high-resolution CT findings indicate PAH, and the imaging findings deteriorate rapidly after antibiotic therapy.