Oregon Health & Science University-led research is reporting that daily full-body emollient use starting before 9 weeks of age lowered atopic dermatitis incidence by 24 months in a representative US infant cohort.
Children with early atopic dermatitis often develop food allergy or asthma, and studies have observed associations between skin barrier dysfunction and later allergic disease. More than 10 trials have tested skin-barrier enhancement; full-body emollient evidence in general-risk primary-care populations remains limited.
In the study, “Emollients to Prevent Pediatric Eczema,” published in JAMA Dermatology, researchers randomized infants to determine whether once-daily emollient application reduces atopic dermatitis incidence by age 24 months.
A total of 1,247 infant-parent dyads were recruited from 25 community clinics in Colorado, North Carolina, Oregon, and Wisconsin.
Caregivers applied a bland, study-supplied moisturizer to the infant’s entire body every day, beginning before 9 weeks old, excluding scalp and diaper area if preferred.
Control families were asked to refrain from routine emollient use. Surveys captured adverse events and skin-care habits, and trained coordinators, masked to assignment, abstracted physician-recorded diagnoses from electronic health records.
By 24 months, physician-diagnosed atopic dermatitis affected 36.1 % (SE 2.1) of the moisturizer group versus 43.0 % (SE 2.1) of controls, relative risk 0.84 (95 % CI 0.73–0.97; P = .02).
Analysis showed that infants without a first-degree family history of atopy had a stronger response to the intervention (RR 0.75; 95 % CI 0.60–0.90; P = .01), while those with a family history had a non-significant risk reduction (RR 0.93; 95 % CI 0.78–1.11).
Unexpectedly, infants classified as low risk (without a family history of atopy) had slightly higher baseline rates of atopic dermatitis than high-risk infants in both arms of the trial. In the control group, cumulative incidence was 43.4 % in low-risk infants vs 42.5 % in the high-risk. Among those receiving the emollient intervention, incidence was 33.2 % in low-risk and 39.1 % in high-risk.
While the study was not designed to interpret this anomaly, it is likely that families with a history of atopy already take countermeasures to reduce causes of skin irritation, whereas the lack of family history in the low-risk group possibly had more baseline exposure.
Another interesting note was that the protective effect was significantly stronger in households with a dog (RR 0.68; 95 % CI 0.50–0.90; P = .01).
Authors calculated a number-needed-to-treat of 15, essentially meaning that if 15 infants undergo the treatment it will be effective for one of them. The other 14 infants would see no additional eczema-prevention benefit relative to what would have happened without the routine. Additionally, it would seemingly only lower eczema burden among those in low-risk categories, but offer no significant benefit for those at high risk.