[Acute eosinophilic pneumonia with positive response to smoking challenge test, suggesting the involvement of health food].

A 17-year-old girl was admitted to our hospital because of acute febrile illness, progressive dyspnea and severe hypoxemia. Chest radiography and HRCT showed bilateral diffuse ground-glass opacities, consolidation, Kerley lines and pleural effusion. Analysis of bronchoalveolar lavage fluid showed 41.9% eosinophils, and a transbronchial lung biopsy revealed infiltration of eosinophils into the alveolar septa and mild alveolar septal edema. The patient's condition was improved immediately by corticosteroid therapy. She had begun smoking and taking health food (chitosan) 3 months before the admission. A smoking challenge test was positive and a drug-induced lymphocyte stimulation test for chitosan was positive. These findings suggested acute eosinophilic pneumonia caused by smoking and health food. The concentration of interleukin-5 (IL-5) in the serum and BALF/granulocyte colony-stimulating factor (G-CSF) in the serum on admission were very high, but decreased after the improvement. Therefore, it is likely that IL-5 and G-CSF are important in the onset of acute eosinophilic pneumonia.