Association of frequent moisturizer use in early infancy with the development of food allergy

Abstract

Background: Food allergy is thought to develop through transcutaneous sensitization, especially in the presence of skin barrier impairment and inflammation. Regular moisturizer application to infant skin could potentially promote transcutaneous sensitization and the development of food allergy.

Objectives: We tested this hypothesis in the Enquiring About Tolerance (EAT) study population.

Methods: The EAT study was a population-based randomized clinical trial conducted from January 15, 2008, to August 31, 2015, and recruited 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 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.

Results: 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% CI, 1.13-1.27; P < .0005) for developing food allergy. For infants with no visible eczema at the enrollment visit, the corresponding adjusted odds ratio was 1.18 (95% CI, 1.07-1.30; P = .001) and for those with eczema at the enrollment visit, 1.20 (95% CI, 1.11-1.31; P < .0005). Moisturizer frequency showed similar dose-response relationships with the development of both food and aeroallergen sensitization at 36 months.

Conclusions: These findings support the notion that regular application of moisturizers to the skin of young infants may promote the development of food allergy through transcutaneous sensitization.

Keywords: Moisturization; TEWL; allergy prevention; children; eczema; filaggrin; food allergy; skin barrier.

Graphical abstract

Fig 1

Moisturization frequency at 3 months and food allergy (left panels) and 3 months TEWL (right panels), by visible eczema status at the 3-month visit: no visible eczema (A), visible eczema (B), and all participants (C). Note change of scale of axes between panels. Left-hand panels include participants with (i) visible eczema status at enrollment determined, (ii) enrollment general questionnaire completed including the moisturization frequency question, and (iii) their primary outcome status determined. Right-hand panels include participants with (i) and (ii) as described for the left-hand panels and (iii) TEWL measurement undertaken at enrollment.

Fig 2

Moisturization frequency at 3 months and food allergy (crude and adjusted analysis), by visible eczema status at the 3-month visit: no visible eczema (A), visible eczema (B), and all participants (C). Left-hand panels show the results for moisturization frequency as a categorical variable, with the never moisturized category as baseline (OR, 1.0). Right-hand panels show the results for moisturization frequency treated as a continuous variable with the OR shown being for each unit increase in weekly moisturization frequency. Crude (unadjusted) analysis restricted to participants with complete covariate data. Adjusted analysis was adjusted for study group, sex, number of siblings, number of family members with history of eczema, ethnicity, eczema severity (SCORAD) (B and C), filaggrin mutation status, and TEWL.

Fig 3

Moisturization frequency at 3 months and food (left panels) and aeroallergen (right panels) sensitization at 36 months, by visible eczema status at the 3-month visit: no visible eczema (A), visible eczema (B), and all participants (C). Note change of scale of axes between panels.

Fig 4

Moisturization frequency at 3 months and the development of visible eczema at 12 months (A) and 36 months (B), among infants with no visible eczema at the 3-month visit. Note change of scale of axes between panels.

Fig E1

EAT enrollment and randomization. Baseline visits occurred when participants were 3 months of age. The primary outcome for the EAT study was challenge-proven food allergy to 1 or more of the 6 early introduction foods between 1 and 3 years of age. ^aEight infants randomized to each group were found to have significant health issues either on blood testing or the clinical examination at the enrollment visit, rendering them ineligible for enrollment: conditions included severe vitamin D deficiency, severe iron deficiency, severe failure to thrive, familial hypercholesterolemia, congenital stridor, epidermolysis bullosa, and cartilage hair hypoplasia syndrome. ^bForty-three participants in the SIG and 69 participants in the EIG withdrew voluntarily from the study. Reasons given were as follows: concerns about the blood tests (SIG 0, EIG 2), emigration (SIG 10, EIG 12), expenses (SIG 1, EIG 1), family health issues (SIG 3, EIG 0), family issues (SIG 2, EIG 4), no reason given (SIG 11, EIG 16), lost contact with family (SIG 15, EIG 28), too far to travel for study assessments (SIG 0, EIG 1), and unhappy participating in the study (SIG 1, EIG 5). ITT, intention-to-treat.