Moisturizing babies sensitizes them to food allergies

Regular use of moisturizers in infants may promote transcutaneous sensitization and the development of food allergies, a recent study has found.

Enrolling from the Enquiring About Tolerance study, researchers surveyed families about their use of moisturizers and corticosteroid creams, and about dry skin or eczema, in a total of 1,302 exclusively breastfed infants. Skin prick testing and subsequent food challenge were used to assess allergies.

At baseline, 24.4 percent (n=317) of the participating infants had clear and visible signs of eczema, while the remaining 75.6 percent (n=985) did not. Among infants without eczema, 654 were being moisturized at least once a week; parents who reported that their children had dry skin or eczema (despite having no such signs at the 3-month visit) were more likely to moisturize more frequently.

Excluding those with a history of eczema and/or parent-reported dry skin yielded a final group of 712 infants who phenotypically appeared to have healthy skin. Moisturization was still high in this group, with 66 percent being moisturized at least once a week.

In turn, moisturization frequency correlated significantly with the likelihood of having food allergies in a dose-dependent manner. This remained true even when stratifying infants according to those with and without visible eczema at baseline.

When taken as a continuous variable, each additional moisturization per week correlated with an 18-percent jump in the odds of developing food allergies for infants without visible eczema at enrolment (odds ratio [OR], 1.18, 95 percent confidence interval [CI], 1.07–1.30; p=0.001).

This effect was slightly stronger among those with visible eczema at baseline, such that each additional moisturization per week increased the likelihood by 20 percent (OR, 1.20, 95 percent CI, 1.11–1.31; p<0.005).

“Taken together, our findings and those of prior studies suggest that emollients may facilitate transcutaneous sensitization to both food and aeroallergens,” the researchers said. “These findings are potentially of great significance, and further research is required to understand the mechanism of action.”