[Characteristics of shrimp allergy from childhood to adulthood in Japan].

Objective: We examined profiles and clinical symptoms of shrimp allergy patients and investigated the correlation of shrimp-specific IgE to crustaceans-specific IgE, mollusks-specific IgE and shellfish-specific IgE. In addition, symptoms when eating crustaceans other than shrimp, mollusks and shellfish were examined, because they shared tropomyosin as a major allergen.

Methods: We examined 99 definitive shrimp allergy cases with questionnaire.

Results: Their onset started during either childhood or young adulthood. Symptoms appeared within an hour after ingestion of shrimp in 87.9% cases. The most common symptoms were skin symptoms, followed by oral allergic syndrome (OAS) like symptoms, respiratory symptoms. Anaphylaxis were observed in 61 cases including 2 anaphylactic shock cases. Among 99 shrimp allergy cases, 44 cases (64.7%) showed positive reaction to crabs out of 68 cases experiencing crab ingestion. Only 11 cases (17.5%) reacted against squid out of 63 cases with the experience in squid ingestion. Crab-specific IgE (C.I. 0.954, p < 0.001) and squid-specific IgE (C.I. 0.582, p > 0.001) were strongly correlated with shrimp-specific IgE.

Conclusion: We conclude that a lot of cases with shrimp allergy react to crabs clinically, and which seem to be different from the reaction against mollusk and shellfish intake in spite of sharing tropomyosin as a major allergen among them.