Seafood graded oral food challenge outcomes in a care center

Background: There are sparse data regarding the predictors of positive oral food challenges and reaction severity for seafood in children. Objective: Identify clinical characteristics in children with seafood allergy who were most likely to experience a negative oral food challenge (OFC). Methods: A retrospective chart review was performed for children who had a graded OFC to seafood at a pediatric tertiary care center from 2008 through 2019. Results: Sixty-three (60% male; average age 8 years; range 1-21 years) OFCs were performed, of which 21 were fish and 42 were shellfish. There were 10 (16%) positive OFCs and positive OFC rate was similar between fish (19%) and shellfish (14%). Forty-three children who underwent OFC had a reported history of IgE-mediated symptoms. Five of six children who had a history of anaphylaxis had a negative OFC. There was no difference in positive OFCs due to age, history of atopy, or initial allergic reaction history. The clinical characteristics of the positive OFCs were similar between fish and shellfish. A positive skin prick test to fish or shellfish did not increase the risk of a positive OFC. While the positive OFC rate did not differ for the shellfish food-specific IgE (FSIgE) level, there was a significant difference for fish (median <0.34 kU(A)/L vs. 1.63 kU(A)/L for pass and fail, respectively; P = 0.023). Conclusion: A retrospective study of OFCs to seafood showed that the rate of a positive OFC was low. While seafood allergy is thought to be rarely outgrown, children who have a low FsIgE and/or skin testing can successfully tolerate seafood.