Skin barrier impairment at birth predicts food allergy at 2 years of age

Maeve M. Kelleher, Audrey Dunn-Galvin, Claire Gray, Deirdre M. Murray, Mairead Kiely, Louise Kenny, W.H. Irwin McLean, Alan D. Irvine, Jonathan O'B. Hourihane

Transcutaneous exposure to food allergens can lead to food sensitization (FS)/food allergy (FA). We measured skin barrier function in early infancy and related it to the later development of FS/FA at age 2 years. We sought to examine the relationship between early life skin barrier function and FA in infancy. Infants in the Babies After Scope: Evaluating the Longitudinal Impact Using Neurological and Nutritional Endpoints (BASELINE) birth cohort had transepidermal water loss (TEWL) measured in the early newborn period and at 2 and 6 months of age. At age 2 years, infants had FS/FA screening with skin prick tests and oral food challenges. One thousand nine hundred three infants were enrolled. One thousand three hundred fifty-five were retained to age 2 years, and 1260 underwent FS screening. FS was present in 6.27% (79/1260; 95% CI, 4.93% to 7.61%), and FA prevalence was 4.45% (56/1258; 95% CI, 3.38% to 5.74%). Egg was the most prevalent allergen (2.94%), followed by peanut (1.75%) and cow's milk (0.74%). Day 2 upper-quartile TEWL (>9 gwater/m(2)/h) was a significant predictor of FA at age 2 years (odds ratio [OR], 4.1; 95% CI, 1.5-4.8). Seventy-five percent of children with FA at 2 years of age had day 2 TEWL in the upper quartile. Even in those without atopic dermatitis (AD), infants with upper-quartile day 2 TEWL were 3.5 times more likely to have FA at 2 years than infants in the lowest quartile (95% CI, 1.3-11.1; P = .04). Neonatal skin barrier dysfunction predicts FA at 2 years of age, supporting the concept of transcutaneous allergen sensitization, even in infants who do not have AD. TEWL could be used for stratifying infants in the first few days of life before development of AD or FA for targeted intervention studies to potentially alter the atopic march.