Egg Allergy and the Skin: The Invisible Face of Epidermal Alteration in Infants

Egg allergy is one of the most common food allergies in early childhood and often coexists with atopic conditions such as atopic dermatitis (AD) and urticaria. Skin-barrier dysfunction plays a critical role in the pathophysiology of allergic diseases. This study aimed to examine the relationship between egg allergy and skin-barrier health by evaluating hydration, sebum, and softness using a noninvasive bioimpedance method.

In this prospective case-control study, 49 children aged 0-2 years with egg allergy and 50 age-matched healthy controls were enrolled between December 2024 and February 2025. In the case group, total and egg-specific IgE levels, eosinophil counts, and skin prick test results were recorded. Skin parameters were measured from the antecubital region using a portable bioimpedance device. Intergroup comparisons were performed using the Mann-Whitney U test. Additionally, an exploratory subgroup analysis compared skin parameters between egg-allergic children with and without AD exacerbation after allergic reaction.

Children with egg allergy had significantly lower skin hydration, sebum, and softness compared to controls (p < 0.001 for all). Total IgE levels were higher in egg-specific IgE-positive patients (p = 0.001), although skin parameters did not differ significantly by IgE status. Among 20 egg-allergic children with follow-up after allergic reactions, those with AD exacerbation had markedly lower moisture, oil, and softness scores than those without exacerbation (p < 0.01 for all comparisons).

Children with egg allergy exhibit both elevated immunologic activity and impaired skin-barrier function. Bioimpedance analysis offers a practical and noninvasive tool for evaluating skin health in allergic infants. Integrating skin-barrier assessment into allergy management may facilitate early intervention and more comprehensive care.