Egg allergen specific IgE diversity predicts resolution of egg allergy in the population cohort HealthNuts

Background IgE‐mediated egg allergy presents as one of the most common food allergies in children. Measurement of egg white specific IgE (sIgE) levels in serum or skin prick test has been shown to be a poor predictor of clinical allergy to raw egg white, and also to baked or cooked egg. Recent developments in component resolved diagnostic (CRD) technology have enabled us to improve the way in which we diagnose and predict peanut allergy by examining IgE specificity to individual peptides. Objectives We aimed to investigate whether egg CRD could improve current methods to diagnose various egg allergy phenotypes as well as predict the development of tolerance to egg. Methods Using the HealthNuts cohort of food challenge‐proven egg allergic and egg‐sensitized and egg‐tolerant, age‐matched 12‐month infants with longitudinal follow‐up at 2 and 4 years (n = 451), we measured serum egg white, Gal d 1, 2, 3 and 5 sIgE using ImmunoCAP. Results Gal d 1 sensitization increased the risk of persistent egg allergy by 2.5‐fold. The production of sIgE to all four egg allergens (Gal d 1, 2, 3 or 5) increased the risk of having persistent raw egg allergy fourfold (OR 4.19 (95% CI: 1.25‐14.07). We did not find any improvements of using Gal d 1, 2, 3 or 5 to diagnose current egg allergy compared to egg white sIgE. Conclusion Sensitization to multiple egg allergens Gal d 1, 2, 3 or 5 may be a prognostic marker that could be useful for patient management and identifying individuals at risk of developing persistent egg allergy. Sensitisation to Gal d 1 increases the risk of persistent egg allergy later in life (OR 2.5). Sensitisation to any of the 3 or 4 major egg allergens Gal d 1, 2, 3 or 5, increases the risk of persistent egg allergy (OR 4.19). The use of egg CRD does not improve the accuracy of egg allergy diagnosis compared to current whole egg sIgE 95% PPV.