Clarithromycin-induced eosinophilic pneumonia.

Clarithromycin (CAM) has been widely used for the treatment of respiratory infection. Macrolides are generally well tolerated and their adverse reactions are rare. An 80-year-old woman with nontuberculous mycobacterium infection was treated with combined chemotherapy, including isoniazid, rifampicin, and ethambutol. She developed a fever and peripheral blood eosinophilia, and new subpleural consolidations were observed on chest radiography three days after add-on therapy with CAM. The symptoms and clinical findings improved with the withdrawal of CAM. Histopathologic examinations confirmed the diagnosis of eosinophilic pneumonia. This is the first report of CAM-induced eosinophilic pneumonia.