Granulomatous interstitial pneumonia induced by the intake of rice bran pickles: a rare subtype of pulmonary manifestation associated with food allergy.

Pulmonary manifestations associated with food allergy are rich in variety. We report the first case of food-induced granulomatous interstitial pneumonia mimicking hypersensitivity pneumonitis (HP). A 77-year-old woman with respiratory symptoms was referred to our hospital. We performed a surgical lung biopsy, which showed the features of granulomatous interstitial pneumonia. Her clinical history resembled those observed in HP. However, avoidance of exposure to the causative antigens did not improve her symptoms. Moreover, the patient had some features inconsistent with HP, such as elevated serum IgE levels, blood eosinophilia, intrathoracic lymphadenopathies and pleural effusion. Therefore, we pursued another extrinsic non-inhaled antigen as the cause of pulmonary involvements. We noted that she had been eating homemade rice bran pickles, and pulmonary involvements were induced by an ingestion challenge test. We suggest that granulomatous interstitial pneumonia may be a rare subtype of the pulmonary manifestations associated with food allergy.