[A case of acute eosinophilic pneumonia that developed after changing cigarette brands]

A 20-year-old man visited a clinic with high fever and a dyspnea. The chest X-ray film and CT showed multiple patchy ground glass opacities in all lung fields with thickened interlobular septa and bilateral pleural effusions. Examination of bronchoalveolar lavage fluid led to a diagnosis of acute eosinophilic pneumonia. The patient was a current smoker and he had changed the brand of cigarette he smoked from one with a filter to another brand without filter, one week before disease onset. His symptoms improved after the administration of methylprednisolone. This case suggested that the presence of a filter or a difference in ingredients, or both, between brands of cigarette might contribute to the development of acute eosinophilic pneumonia.