[Pulmonary infiltration with eosinophilia due to rabbit-fur antigen: diagnosis by allergen inhalation test]

We report the case of a 48-year-old man with asthma and pulmonary eosinophilia. He presented with coughing, dyspnea, and wheezing that began 6 months after he began keeping a rabbit in his house. He was referred to our department for further examination of pulmonary infiltrative shadows. An inhalation test with rabbit-fur antigen induced both immediate and late asthmatic responses. In addition, infiltrative shadows appeared in the right segments 2, 8, and 9 on chest CT films after the antigen inhalation. Examination of fluid obtained by bronchoalveolar lavage from the right S9 showed an increase in the fraction of eosinophils. Examination of a specimen obtained by transbronchial lung biopsy from those segments revealed infiltration of inflammatory cells into the alveolar septa and alveolar spaces, which was consistent with eosinophilic pneumonia. Our diagnosis was asthma and pulmonary eosinophilia due to rabbit-fur antigen.