Asthma and contact urticaria caused by rice in a housewife

We report the case of an atopic housewife who presented with rhinoconjunctivitis-asthma and contact urticaria from handling rice and other cereals. She tolerated cooked cereals. Both skin prick tests with a rice extract (20% w/v) and a rub test with raw rice gave positive results. Bronchial challenge test with methacholine revealed a PC₂₀ of 0.45 mg/ml. The challenge test with raw rice resulted in immediate and late clinical and spirometric responses; pretreatment with DSCG inhibited both responses. The histamine release test (HRT) with rice was positive, and we detected rice-specific IgE antibodies by REIA in the patient's serum. Skin prick tests, HRT, and RAST with a battery of cereals gave positive results. Finally, the rice REIA was inhibited by rice (75%), rye (63%), corn (64%), and wheat (51%) extracts.