Association of Frequent Moisturizer Use in Early Infancy With the Development of Food Allergy

Abstract

It has been hypothesized that food allergy may develop through transcutaneous sensitization, especially in the presence of skin barrier impairment and inflammation. With this study, researchers sought to determine if regular moisturizer use in infants could potentially promote food sensitization and the development of food allergy.This hypothesis was studied in the Inquiring About Tolerance study population. The Inquiring About Tolerance study was a population-based randomized clinical trial conducted from January 15, 2008, to August 31, 2015, including 1303 exclusively breastfed 3-month-old infants and their families from England and Wales.At enrollment at 3 months, families completed a questionnaire that included questions about the frequency and type of moisturizer applied, use of corticosteroid creams, and parental report of dry skin or eczema. Infants were examined for visible eczema at the enrollment visit.A statistically significant dose-response relationship was observed between parent-reported moisturization frequency at 3 months of age and the subsequent development of food allergy. Each additional moisturization per week was associated with an adjusted odds ratio of 1.20 (95% confidence interval [CI]: 1.13 to 1.27; P < .0005) for developing a food allergy. For infants with no visible eczema at the enrollment visit, the corresponding adjusted odds ratio was 1.18 (95% CI: 1.07 to 1.30; P = .001), and, for those with eczema at the enrollment visit, corresponding adjusted odds ratio was 1.20 (95% CI: 1.11 to 1.31; P < .0005). Moisturizer frequency revealed similar dose-response relationships, with the development of both food and aeroallergen sensitization at 36 months.These findings support the idea that regular application of moisturizers to the skin of young infants may promote the development of food allergy through transcutaneous sensitization.The notion of transcutaneous sensitization has become popular over the past decade, and there is now an increasing body of research to support it. In short, it is hypothesized that early oral exposure is likely to induce tolerance, whereas skin exposure is more likely to lead to sensitization. This appears to be especially common in infants with eczema, likely because of both an impaired skin barrier and a greater inherited predisposition to develop allergy. It is also interesting to note that other studies have suggested that early and aggressive eczema care might prevent food allergy. There may therefore be a precarious balance, with the likely tipping point being the presence of allergen on the hands of the person applying the moisturizer.