ABSTRACT
We report a case of drug-induced pneumonia associated with the herbal medine Syakuyakukanzo-to. A 82-year-old man was admitted to our hospital complaining of cough, fever, and dyspnea after administration of shakuyakukanzoto for two weeks. Drug-induced lymphocyte stimulation tests were negative, but bronchoalveolar lavage showed an increase in lymphocytes with an increased CD4/CD8 ratio. Cessation of the drug improved the patient's clinical and X-ray findings and then he was able to be discharged. He was admitted again for a challenge test. His clinical symptoms and X-ray findings became worse 8 days after re-administration, therefore we diagnosed drug-induced pneumonia caused by Shakuyakukanzoto. He has had no recurrence after discontinuance of the drug. To the best of our knowledge, there has been no previous case of drug-induced pneumonia due to Shakuyakukanzo-to reported in the world.