Helen Brough, MA, MSc, PhD, MBBS, FAAAAI, FRCPCH, discusses the role of AD skin in infants and emollient application for preventing food allergy.
Food allergies are dramatically more prevalent in infants with atopic dermatitis (AD) than those without. One study1 found that 1 in 5 infants with AD had allergies to peanuts, sesame or egg whites, compared to 1 in 25 infants without AD. As Helen Brough, MA, MSc, PhD, MBBS, FAAAAI, FRCPCH, consultant and reader in pediatric allergy at King’s College London said in her presentation at the American College of Allergy, Asthma & Immunology 2021 annual scientific meeting,2 the skin is a key target for preventing and treating food allergies in the pediatric patient population.
Epicutaneous sensitization and damage has a variety of environmental and genetic causes. Anything from detergents and viruses to genetics can contribute. Small studies examining targeted microbiome transplants via topic probiotic creams as a way to address some of these complex causes have been completed.3 However, the evidence based on these studies is inconclusive at this point, though larger trials are underway.
Targeting 1 aspect of these triggers could have a powerful preventative effect, according to Brough. Specifically, a post hoc retrospective review of questionnaires found that frequency of moisturization (predominantly with olive oil) at 3 months and the development of food allergy at 3 years show an elevated risk of allergy for infants moisturized daily or multiple times daily.4 Brough said the analysis adjusted for eczema severity and filaggrin status. The results also persisted when infants whose parents’ reported eczema or dry skin were excluded. Transepidermal water loss (TEWL) increased with the frequency of moisturizer use. Olive oil was the most commonly used moisturizer in infants with and without eczema. Brough emphasized that the majority of parents who used oils did so as a massage in infants with no eczema. Brough said that olive and other vegetable oils impede the development of lamellar structures. Other creams that contain sodium laurel sulfate, a common surfactant, were also used which is known to disrupt the skin barrier. In larger studies, petrolatum-based emollients placed on the skin of infants before they had developed signs or symptoms of AD had no effect on AD prevention, severity, or time of onset but were correlated with an increase in skin infections and a tendency to food allergy.
The question then stands that if petrolatum-based emollients moisturizers have no effect on the prevention AD but pose a risk of allergy development, what preventative tools are in a dermatologist’s armamentarium? Trilipid based emollients applied before the development of AD show positive results in pilot studies, according to Brough. A review5 of infants referred for AD showed that proactive topical steroid treatment resulted in a reduction of allergies by 2 years. In children sensitized to egg, 17% of patients who began treatment within 4 months of the onset of AD developed an allergy compared to 40% of patients who began treatment more than 4 months after onset of AD.
Brough said there are 4 main components that need further research for the preventing atopic dermatitis and food allergies:
Dermatologists need to work with parents and allergists to help prevent the use of allergy-triggering products and the introduction of proactive therapies when necessary.
Brough is an employee of Guy’s and St. Thomas’ NHS Foundation Trust; has served as primary investigator for the National Institutes of Health and a subinvestigator for Aimmune and DBV Technologies and has been on the speakers’ bureau or received honoraria from DBV Technologies and Sanofi.