Fish and shellfish allergy: Presentation and management differences in the UK and US-analysis of 945 patients

Background: Seafood allergy (SA), including allergy to shellfish (crustacean and mollusks) and fish, is among the 4 most common food allergies causing anaphylaxis, but there are limited data showing SA clinical management in different countries.

Objective: We sought to characterize a large cohort of patients with fish and shellfish allergy and to facilitate standardization of future care for this increasingly common allergic disease.

Methods: We performed a retrospective, observational, noninterventional study from 945 patients from 2015 to 2019 in 7 hospitals in the United States and the United Kingdom to evaluate SA. A chi-square test was used to detect differences in family history, medical history, and current symptoms between patients in 2 countries.

Results: Underdiagnosed anaphylaxis in patients with SA was associated with underuse of epinephrine (adrenaline) autoinjectors in both countries. Oral food challenge was used only when skin or serologic test results were negative. Asthma and allergic rhinitis were more common in the US patients with SA, but eczema was more common in UK patients with SA (P < .001). Respiratory, gastrointestinal, and neurological symptoms were higher in UK patients with SA than in US patients with SA (P < .001).

Conclusions: In international multicenter cohorts of patients with fish and shellfish allergy, there are opportunities for improvement in management. Physician identification of anaphylaxis, use of diagnostic oral food challenges, and anaphylaxis treatment with epinephrine are areas with significant knowledge gaps in need of improvement in the United Kingdom and the United States. There is an opportunity for the development of unified, standardized diagnostic protocols for SA with distribution for allergists and trainees.