LOUISVILLE, Ky. -- Eczema during infancy is a known risk factor for the development of food allergies later in childhood, but what role do moisturizers play in altering that risk?
Roughly one in five infants with severe, early onset atopic dermatitis or eczema will develop allergies to peanut or other foods during childhood, said Helen Brough, PhD, MSc, of the Guy's and St Thomas' NHS Foundation Trust in London, in a presentation at the American College of Allergy, Asthma & Immunology annual meeting.
Applying moisturizers and emollients to babies with dry skin and atopic dermatitis is a common practice. But it received increased scrutiny after a suggested that frequent moisturizer use during infancy may increase the risk for developing food allergies.
The study involved both high-risk and low-risk infants in the U.K., and those researchers observed a statistically significant, dose-response relationship between caregiver-reported moisturization and later food allergy. Specifically, each additional moisturization per week was associated with a roughly 20% increase in the risk for developing food allergy (odds ratio 1.20, 95% CI 1.13-1.27, P<0.0005).
However, a showed no significant links between early moisturizer use and later food sensitization. Four studies included in that analysis assessed food sensitization with skin prick testing or specific IgE to food allergens; two studies assessed clinical food allergy. In a pooled analysis, use of moisturizers up to age 12 months did not significantly change the rate of food sensitization to any food in infants compared to control groups (RR 1.10, 95% CI 0.83-1.46, I2=40%).
Brough argued that the type of emollients most often used by the parents in the EAT study may largely explain the sub-analysis findings. She noted that baby massage with olive oil or baby oil is a common practice in the U.K, but rather than strengthening the skin barrier, these oils, along with moisturizers with sodium lauryl sulfate, may disrupt the skin barrier, making the skin more susceptible to bacterial infection.
She added that in mouse studies, having oil on the skin has been shown to facilitate the transfer of bacteria and other pathogens through the skin.
Brough pointed out that in the U.K. "bath oils are not recommended for children with eczema because they are not effective. But maybe bath oils could actually increase the risk for eczema or food allergy."
In 2020, Brough and colleagues reported results from a with 45 children (ages 3 months-7 years) with dry skin or eczema. They found that daily use of trilipid-based moisturizer, but not petrolatum-based moisturizer, for 5 weeks improved skin barrier function, as measured by transdermal water loss.
In another small study, a trilipid-based moisturizer was applied all over the body in 16 infants with dry skin or eczema for 12 weeks. The treatment was tied to increased plasma IgG4:IgE ratio, while use of petrolatum-based moisturizers was associated with a decline in IgG4:IgG. "So maybe these creams could do something not just to the skin barrier, but also to the immune system," Brough said.
She highlighted findings from the pilot phase of the ongoing in Australia. The multicenter, phase III study will recruit more than 700 infants with a family history of allergic disease from maternity hospitals in Melbourne to determine if the application of trilipid, ceramide-containing cream two times/day, 5 days a week, for 6 months reduces the risk of atopic dermatitis and food allergy.
In early data in 91 children, controls who were not treated with the moisturizers had 8.3% sensitization to peanut at age 12 months versus 0% sensitization among those who got trilipid cream (n=21), Brough said. In addition, sensitization to milk and egg in the pilot controls was 5.6% and 16.7%, respectively, versus 0% for both in the trilipid-cream group. And the presentation of atopic dermatitis at 12 months was 15% in the control arm versus 5% in the intervention arm.
She noted that the early PEEBLES findings "did not quite reach statistical significance because the numbers were small, but there is definitely a signal there."
She stressed that there are still many unknowns about the relationship between moisturizer use and eczema/food allergy risk, but there's more clarity on other issues, such as an association between oils and an increased eczema risk. On other other hand, trilipid-based creams appear to protect against eczema and possibly food allergy.
"We know that it is really important that families who use moisturizers on their babies wash their hands before they apply it, to reduce the risk for causing skin infections, and the best time to apply it is after a bath because that's when the baby and the [caregiver] will have clean hands," Brough stated.
Disclosures
Brough disclosed relationships with, and/or support from, DBV Technologies, GSK, Sanofi, and Aimmune.