[A case of loxoprofen-induced pneumonitis pathologically resembling hypersensitivity pneumonitis].

A 66-year-old woman was admitted to our hospital because of high fever, general fatigue, hypoxemia and liver dysfunction. Chest radiographs showed diffuse interstitial shadows in both lungs. We suspected drug-induced pneumonitis because of her history of drug administration for upper respiratory infection. Her symptoms and findings were markedly decreased by discontinuation of the drugs. Transbronchial lung biopsy specimens showed infiltration of eosinophils and lymphocytes to the alveolar septa, granuloma with Langhans' giant cells, and Masson bodies in a manner suggestive of hypersensitivity pneumonitis. Drug lymphocyte stimulation tests were negative except for loxoprofen. There was no recurrence of systemic or respiratory symptoms during overnight stays at home. On the basis of these findings, we arrived at a diagnosis of drug-induced pneumonitis caused by loxoprofen.