A case of occupational rhinitis caused by rice powder in the grain industry

Rice is the major staple food in a large part of the world, especially in Asia. Hypersensitivity reactions to rice are rare. Moreover, cases of occupational allergies induced by inhalation of rice powder are uncommon. We report a 31-year-old male with work-related rhinitis and conjunctivitis symptoms caused by occupational exposure to rice powder in the grain industry. He showed positive responses to rice extracts on a skin prick test, and a high level of serum specific IgE to rice was detected by ELISA. Occupational rhinitis was confirmed by a nasal provocation test with rice extracts. An IgE ELISA inhibition test showed cross-creativity between rice and various grass pollen extracts. These findings suggest that the inhalation of rice powder can induce IgE-mediated occupational rhino-conjunctivitis, which may be derived from cross-reactivity to major grass pollens.