[Case of drug-induced pneumonitis associated with a dietary supplement containing CoQ10].

A 61-year-old woman began to take a dietary supplement contained CoQ10 and perilla leaf extract. Two months later, a dry cough appeared. The number of eosinophils in peripheral blood was elevated and chest radiograph images showed infiltrative shadows in the left middle lung. A chest CT scan showed consolidation in the left upper lobe (S3) and lower lobe (S10). The percentage of eosinophils was abnormally high in bronchoalveolar lavage fluid (BALF), and examination of a transbronchial lung biopsy (TBLB) specimen showed marked infiltration of eosinophils in the alveolar wall. Drug lymphocyte stimulation test (DLST) indicated high stimulation index for both supplement containing CoQ10 and its element of CoQ10. We diagnosed drug-induced pneumonitis, caused by CoQ10. The symptoms of the patient and pulmonary infiltrative shadows on chest radiograph improved after she stopped taking the supplements and started taking prednisolone orally. Recently various dietary supplements are coming onto the market. Since the possible adverse effects of these supplements are not investigated extensively, care should be taken for symptoms relating to food supplements.