Phenotypes of persistent hen`s egg allergy in children and adolescents.

Background: Optimum management of food allergy (FA) includes consideration of co-allergies and multimorbidities and tolerance assessment. Documentation of FA practices may pave the way for better practice.

Methods: Patients aged 3-18 years, with persistent IgE-mediated hen`s egg allergy were reviewed.

Results: A total of 102 children with a median age of 59 months (IQR= 40-84) (72.2% males) were included. All were diagnosed during infancy and the initial symptoms were atopic dermatitis (65.6%), urticaria (18.6%), and anaphylaxis (5.9%). Of the total population, 21 (20.6%) experienced anaphylaxis with hen`s eggs, and 79.4%, 89.2%, and 30.4% had multiple FAs (≥2 food categories), ever atopic dermatitis, and asthma, respectively. The most common co-allergies were tree nuts, cow`s milk, and seeds, respectively. From 52 heated egg yolk and 47 baked egg oral food challenges, 48 (92.3%) and 41 (87.2%) were found as tolerant, respectively. The baked egg nontolerant group had a greater egg white skin prick test diameter [9 mm (IQR: 6-11.5) vs. 6 mm (IQR: 4.5-9); (p=0.009)] and specific IgE [12.6 kU/L (IQR: 4.11-45.4) vs. 6.2 kU/L (IQR: 1.9-12.4) (p=0.009)], respectively. In the multivariate analysis, baked egg tolerance was more likely in those with egg yolk-tolerant subgroup (OR: 6.480, 95% CI: 2.524-16.638; p < 0.001) and heated egg tolerance in those with baked egg tolerance (OR: 6.943, 95% CI: 1.554-31.017; p=0.011).

Conclusions: Persistent hen`s egg allergy is characterized by multiple food allergies and age-related multimorbidities. Baked egg and heated egg yolk tolerance were more likely to be considered in a subgroup with a high expectation for finding a way to eliminate their allergy.