Shellfish Hypersensitivity

Abstract: Shellfish are diverse, serve as main constituents of seafood, and are extensively consumed globally because of their nutritional values. Consequently, increase in reports of IgE-mediated seafood allergy is particularly food associated to shellfish. Seafood-associated shellfish consists of crustaceans (decapods, stomatopods, barnacles, and euphausiids) and molluskans (gastropods, bivalves, and cephalopods) and its products can start from mild local symptoms and lead to severe systemic anaphylactic reactions through ingestion, inhalation, or contact like most other food allergens. Globally, the most commonly causative shellfish are shrimps, crabs, lobsters, clams, oysters, and mussels. The prevalence of shellfish allergy is estimated to be 0.5-2.5% of the general population but higher in coastal Asian countries where shellfish constitute a large proportion of the diet. Diversity in allergens such as tropomyosin, arginine kinase, myosin light chain, and sarcoplasmic binding protein are from crustaceans whereas tropomyosin, paramyosin, troponin, actine, amylase, and hemoyanin are reported from molluskans shellfish. Tropomyosin is the major allergen and is responsible for cross-reactivity between shellfish and other invertebrates, within crustaceans, within molluskans, between crustaceans vs. molluskans as well as between shellfish and fish. Allergenicity diagnosis requires clinical history, in vivo skin prick testing, in vitro quantification of IgE, immunoCAP, and confirmation by oral challenge testing unless the reactions borne by it are life-threatening. This comprehensive review provides the update and new findings in the area of shellfish allergy including demographic, diversity of allergens, allergenicity, their cross-reactivity, and innovative molecular genetics approaches in diagnosing and managing this life-threatening as well as life-long disease.

Abstract: Background: Shellfish hypersensitivity is amongst the most common food allergies. The major shellfish allergen was identified as tropomyosin. Here, we investigated the immediate hyp

Abstract: 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.

Abstract: [Extract] The rise in shellfish allergy incidence, accompanying an increase in consumption and exposure to shellfish allergens, has become a serious problem worldwide. Precise diagnosis of shellfish allergy poses a challenge due to the diversity of consumed species, and immunological cross-reactivity to similar invertebrate pan-allergens. Moreover, variable concentrations of major and minor allergens in diagnostic preparations often result in false-negative results.