Early Skin Exposure May Cause Peanut Allergies in Children

It turns out that a child may become allergic to a food without even eating it. Scientists have found that skin exposure to peanuts and food allergens could contribute to early sensitization and could cause allergies in children.

Finding out what causes peanut allergies is crucial, especially considering the extremity of some reactions. About one to two percent of the population is allergic to peanuts, and this particular allergy can be lifelong.

Past studies have shown that children may first become allergic when exposed to peanut proteins through breast milk or in house dust. This current study, though, reveals that skin exposure could also contribute.

In order to better understand what causes peanut allergies, the researchers exposed mice to peanut protein extract on their skin. Then, they watched what happened when they repeated topical exposure to peanut allergens. In the end, they found that these repeated exposures resulted in sensitization and severe, whole-body allergic reaction upon a second exposure.

"The peanut protein responsible for the most allergic reaction in humans is seen as foreign or dangerous by the immune system of the skin," said Cecilia Berin, one of the researchers, in a news release. "Blocking those immune pathways activated in the skin prevented the development of peanut allergy in the mice, and our next step will be to confirm this in humans."

The findings reveal that skin exposure to food allergens can contribute to sensitization to foods in early life. Not only that, but it opens up another path of research when it comes to preventing these allergies.

"This research helps us to understand why peanut, out of the many foods in our diet, is such a common cause of food allergy," said Berin. "If we identify how the immune system recognizes peanut as a danger, we may eventually learn how to block that pathway and prevent the food allergy altogether."

The findings are published in the Journal of Clinical Investigation.