A case of occupational contact urticaria and oral allergy syndrome due to seafood]

A 20-year-old woman was referred for evaluation after about 2 years of recurrent episodes of localized urticaria during handling of several kinds of raw fish in a sushi shop, where she had worked part-time for 2 years. She had also experienced allergic symptoms such as itching and swelling of her lips, generalized urticaria, laryngeal tightness, stridor and dyspnea immediately after ingestion of raw and cooked seafood, including sole, horse mackerel, sea eel and shellfish, over the previous 1 year before referral. Skin prick tests and blood test for specific IgE antibodies were positive for many kinds of seafood, including sole, horse mackerel, sea eel, eel, crab, and abalone, which belonged to different taxonomic phyla, including Chordata, Arthropoda, and Mollusca. A challenge with a piece of broiled sole induced swelling of the lips, obstruction of the larynx, difficulty with deglutition, and abdominal pain. In addition, serum-specific IgE antibodies to two major fish allergens, parvalbumin and collagen, were detected by ELISA, suggesting that allergic symptoms could be induced by many kinds of seafood in the present patient. She was therefore diagnosed with occupational contact urticaria and oral allergy syndrome due to seafood. At the time of this report, the present patient had been followed for one year and no reactions have occurred since she started to avoid the causative types of seafood.