Coexisting genetic and environmental factors may trigger food allergies, according to a study published online in the Journal of Allergy and Clinical Immunology (Feb. 15, 2018). Specifically, these factors include genetic predisposition to skin barrier defects, use of infant cleansing wipes that leave soap residue, skin exposure to allergens such as dust, and skin exposure to food allergens from caregivers.
“This is a recipe for developing food allergy,” said study author Joan Cook-Mills, PhD, professor of allergy-immunology at Northwestern University Feinberg School of Medicine in Chicago, in a press release. “It’s a major advance in our understanding of how food allergy starts early in life.”
Neonatal mice engineered with the genetic mutations associated with atopic dermatitis in humans were used in the study.
First, murine skin was exposed to environmental and food allergens like peanuts, dust (Alternaria alternata mould), and sodium lauryl sulfate, a soap present in infant cleansing wipes. The neonatal mice received three to four cutaneous exposures of these allergens for 40 minutes during a two-week period. Then, they were fed orally with eggs or peanuts.
Results showed that changes in skin barrier function can influence the development of allergic reactions to food allergens. Mice had allergic reactions at the site of skin exposure and allergic reactions in the intestine, as well as anaphylaxis. Notably, neonates of allergic mothers had elevated responses to sensitization with the food allergens.
Researchers say that avoiding these potential triggers may prevent children from developing food allergies later in life. Copyright-free photo courtesy of Pixabay.com.
Furthermore, the investigation demonstrated that skin problems that occur with skin barrier mutations may not be visible until long after a food allergy has already started. The mice had normal-appearing skin, and the dry, itchy skin symptomatic of dermatitis did not develop until the mice were a few months old, equivalent to a young adult in human years.
That being said, Dr. Cook-Mills advised that risk factors for developing a food allergy can be altered at home.
"Reduce baby’s skin exposure to the food allergens by washing your hands before handling the baby,” she said. “Limit use of infant wipes that leave soap on the skin. Rinse soap off with water like we used to do years ago.”
According to Dr. Cook-Mills, animal experiments like this provide a basis to test interventions that can better hinder the development of food allergy in human infants and children.