Parents should avoid using infant wipes and thoroughly wash soap off their babies to reduce the risk of childhood food allergies, scientists have warned.
Researchers have hailed a ‘major advance’ in understanding what causes the complaints after tests revealed links between skin damage and intolerance to certain foods.
They suggest that an increasing failure by parents to rinse away soap after washing their babies is contributing to the rise in childhood food allergies.
The top layer of skin is made of lipids, types of fat, which can be disrupted by soap and soapy chemicals in wipes, the team at Northwestern University found.
If a child already carries genes which predisposes them to altered skin absorbency, contact with these chemicals can then heighten risk that comes with exposure to food allergens.
Published in the Journal of Allergy and Clinical Immunology, the ‘recipe’ for childhood food allergies was identified by comparing clinical data with genetic mutations which occur in humans and experiments on neonatal mice involving allergen exposure.
“They (babies) may not be eating food allergens as a newborn, but they are getting them on their skin,” said Professor Cook-Mills, who led the research.
“Say a sibling with peanut butter on her face kisses the baby, or a parent is preparing food with peanuts and then handles the baby.
“Reduce baby’s skin exposure to the food allergens by washing your hands before handling the baby.
“Limit use of infant wipes that leave soap on the skin. Rinse soap off with water like we used to do years ago.”
Clinical evidence shows more than a third of children with food allergies also suffer from eczema.
However, problems that occur with skin barrier mutations may not be visible until long after a food allergy has started.
The neonatal mice in the experiment with the mutations had normal-appearing skin, and the dry, itchy skin of dermatitis did not develop until the mice were a few months old, the equivalent of a young adult in human years.
After the mice received three to four skin exposures of food and dust allergens for 40 minutes during a two-week period, they were then given egg or peanut by mouth.
They suffered allergic reactions at the site of the skin exposure and in the intestine, as well as anaphylaxis.
“This is a recipe for developing food allergy,” said Professor Cook-Mills.
“It’s a major advance in our understanding of how food allergy starts early in life.”