Case of acute eosinophilic pneumonia possibly caused by an increase in smoking amount

: An 18-year-old man was hospitalized with fever, dry cough and dyspnea of acute onset. A chest radiograph and chest CT scan revealed diffuse bilateral infiltrates in peripheral lung zones with a small amount of pleural effusion. Laboratory data showed leukocytosis without eosinophilia and hypoxemia. Analysis of bronchoalveolar lavage fluid disclosed an increased proportion (75.5%) of eosinophils. There was no evidence of bacterial, fungi or parasite infection and no history of medication. A diagnosis of acute eosinophilic pneumonia was made on the basis of the findings and the disease was considered to be associated with cigarette smoking because the quantity of his smoking increased after he had been smoking for a year. A challenge test was performed in which he smoked cigarettes, which elicited fever, coughing and dyspnea again, thus the smoking challenge test was positive. In conclusion, the increased amount of cigarette smoking appears to have induced acute eosinophilic pneumonia.