A Comparison Of Food Allergic Patients With And Without Atopic Dermatitis

Food allergy (FA) in atopic dermatitis (AD) occurs because food allergens penetrate a dysfunctional skin barrier to induce sensitization. It is unknown whether FA patients without AD have a defective skin barrier, and in what capacity the skin may affect FA. This study compared clinical characteristics and skin barrier function of FA patients with and without AD. 469 food allergic patients from age 0-18 years were included in this study and divided into groups with or without a history of AD. FA was defined based on a history of an immediate clinical reaction with a positive skin prick test or specific IgE level. 6 non-AD peanut allergic patients and 6 non-atopic controls had skin barrier assessment with transepidermal water loss (TEWL) measurements and skin tape stripping. AD with FA had a significantly higher occurrence of egg-induced anaphylaxis than FA without AD (p=0.003). In contrast, AD with FA and AD without FA had a similar prevalence of peanut-induced anaphylaxis. Food-specific IgE levels were similar between groups. More AD patients had allergic rhinitis compared to non-AD (p<0.001) but similar proportions had asthma. 3 of 6 non-AD peanut allergic patients had TEWL area-under-the-curve measurements >550 g/m2/h over 20 tape strips compared to 0 of 6 controls. High TEWL patients had increased peanut-specific IgE and anaphylaxis rate. AD has an increased association with egg-induced, but not peanut-induced, anaphylaxis. Allergic rhinitis is more common in AD, suggesting a propensity to the atopic march. Surprisingly, skin barrier abnormalities exist in 50% of FA patients without AD.