Abstract
A 70-year-old woman with sputum and cough was diagnosed with nontuberculous mycobacterial pulmonary disease based on multiple cultures of Mycobacterium shinjukuense and computed tomography (CT) findings of bilateral nodular shadows and bronchiectasis. Treatment was initiated with ethambutol and azithromycin, and rifampicin was added 1 month later. Three weeks after rifampicin therapy, she developed fever and fatigue, and CT revealed bilateral non-segmental infiltrates and a reversed halo sign indicative of organising pneumonia. Rifampicin was discontinued due to suspected rifampicin-induced lung injury, and a subsequent bronchial lung biopsy confirmed organising pneumonia. The patient's fever resolved with discontinuation of rifampicin, and chest imaging showed resolution of the infiltrates. Continuation with ethambutol and azithromycin did not result in fever or new shadows. We need to consider the possibility of drug-induced lung injury when new shadows appear during nontuberculous mycobacterial treatment regimens.