Frequent moisturizing of infants associated with higher food allergy risk
A study involving more than 1,300 infants has identified an association between more frequent application of moisturizers and an elevated risk of the child later developing food allergies.
Published in The Journal of Allergy and Clinical Immunology (Mar. 1, 2021; 147(3):967-976), the research was led by researchers at St. George’s University of London and King’s College London, U.K.
The investigators note that a previous study in 1,394 children tested whether daily use of emollient in the first year could prevent eczema in high-risk children and found that the approach did not prevent the development of the skin condition. That study, published in The Lancet (Mar. 21, 2020; 395(10228):962-972), also observed a non-significant increase in food allergy in the moisturized group compared to the control group.
This more recent study tested the hypothesis that regular moisturization could promote transcutaneous sensitization and food allergy, using the Enquiring About Tolerance (EAT) study population.
The EAT study was a population-based randomized clinical trial conducted from Jan. 15, 2008, to Aug. 31, 2015, and recruited 1,303 exclusively breastfed three-month-old infants and their families from England and Wales. EAT-participating families completed a questionnaire at enrolment and at three months that included questions about frequency and type of moisturizer applied, use of corticosteroid creams, and parental report of dry skin or eczema. The infants were also examined for visible eczema at the enrolment visit.
Investigators found that each additional moisturization per week was associated with a 20% increase in the likelihood of developing food allergy (ORadj 1.20 (95% CI 1.13-1.27), p<0.0005).
The most frequently used product to moisturize infants was olive oil.
One hypothesis proposed by the authors of the paper to explain the sensitization is that some moisturizers may have a damaging effect on the skin barrier, allowing allergens to make contact with the skin immune system more easily. They also suggest that it could be that parents with allergens on their hands from cooking and eating may inadvertently be exposing their infant to greater contact with these allergens when applying the moisturizer.
In a press release from St. George’s University of London, the paper's first author Dr. Michael Perkin, a pediatric allergist, said: “This study does not say that parents should stop moisturizing their children. The results have raised concerns that there may be something in the act of moisturizing that could raise the risk of food allergy development, but we need further work to establish why this might be the case.
“In the meantime, we recommend that parents wash their hands before moisturizing their babies as a precautionary measure. Of course, if children have skin conditions, such as eczema, treatment guidance from their GP, allergist or dermatologist should still be followed.”
Professor Carsten Flohr, a dermatologist from St John’s Institute of Dermatology at King’s College London and Guy’s & St Thomas NHS Foundation Trust and senior author of the paper, said: “Further research is now required to understand the exact mechanisms behind why more regularly moisturized infants appear to be at a higher risk of developing food allergies, and strategies to prevent this from happening then also need to be developed.”