[A case of pneumonitis due to sho-saiko-to].

We reported a case of pneumonitis due to Sho-saiko-to. A 71-year-old woman was admitted to our hospital because of pneumonia. She complained of dry cough, pyrexia and severe dyspnea. Fine crepitation was heard on physical examination of the chest and a chest X-ray film revealed diffuse reticulo-nodular shadow in both lung fields. We suspected summer-type hypersensitivity pneumonitis and followed her up, however her condition deteriorated. Under a suspicion of drug-induced pneumonitis, all drugs were stopped and she was given prednisolone. Consequently her complaints, laboratory data and chest X-ray findings markedly improved. Microscopic examination of a transbronchial lung biopsy specimens showed interstitial pneumonitis. The results of a lymphocyte stimulation test were positive for sho-saiko-to. She gave informed consent after receiving an explanation of the challenge test. She was tested with 2.5 g sho-saiko-to twice and developed high fever and dyspnea with hypoxia, while the chest X-ray film also revealed diffuse infiltrative shadows similar that on admission. Based on these findings, we diagnosed this case as pneumonitis due to sho-saiko-to. To our knowledge, there has been no previous case of pulmonary hypersensitivity due to sho-saiko-to reported in the world.