Shellfish hypersensitivity: clinical and immunological characteristics.

Shellfish is one of the most frequent causes of food allergy. We studied 48 patients (25 male and 23 female) with a mean age of 24.2 +/- 1.8 with shellfish hypersensitivity. A clinical questionnaire was carried out and prick tests were performed using a series of aeroallergens and a battery of extracts of squid, shrimp, lobster, crab, mussel and clam. Prick tests were also performed using raw and boiled extracts from fresh squid, octopus and limpet. Total and specific IgE to these allergens were determined. The most frequent causes of symptoms were shrimp (33 cases) and squid (24 cases). The most frequently found symptoms were Urticaria/angioedema (39 patients), asthma (18 patients) and rhinitis (14 patients). Clinical association was found between Cephalopoedae and Lamelibranquiae (p < 0.05 for clam and p < 0.01 for mussel), but not among both groups and Crustaceans. Association between history and Prick was statistically significant for Crustaceae and Cephalopoedae (p < 0.01) but not for Lamalibranquiae. Association between history and CAP was not found for shellfish. Significant differences among prick-tests with raw and boiled extracts were not found. These results suggest that prick test yields better results than CAP does it, in shellfish hypersensitivity, that clinical association among shellfish hypersensitivity can occurs within the same and different Phylum reflecting common epitopes and that squid, octopus and limpet extracts contain a large amount of heat-stable allergens.