Food allergies in children could be triggered by infant wipes, a new study has found.
Researchers in the US say they're a key factor, along with "the genetics that alter skin absorbency... skin exposure to allergens in dust and skin exposure to food from those providing infant care".
"Food allergy is triggered when these factors occur together," the study, published in the Journal of Allergy and Clinical Immunology, says.
Joan Cook-Mills, professor of allergy-immunology at Northwestern University Feinberg School of Medicine, says the "eureka" moment came when she was reading studies about how compounds could be delivered through the skin using soap.
"I thought, 'Oh my gosh! That's infant wipes!'"
Soap disrupts the top layer of skin, which is made of fats, she says.
"I thought about what are babies exposed to. They are exposed to environmental allergens in dust in a home. They may not be eating food allergens as a newborn, but they are getting them on their skin. 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. "
Testing on mice found allergic reactions to food at sites on their body where they had previously been exposed to food and dust allergens.
Many infant wipe brands sold in New Zealand are soap-free.
The research adds weight to the "hygiene hypothesis" - that allergies are the result of too much cleanliness. Previous studies have found a link between biting nails and exposure to dirt, and avoiding allergies.