Q: My daughter has had bad eczema and reflux. Now at 11 months old, she was tested for allergies, and results were positive for almonds. I had been using a natural eczema cream on her with almond oil, but the allergist tells me you should never use potentially allergenic food products such as nut oils on eczema, that this can “promote” allergy. Could such a cream cause an allergy?
Dr. Sharma: How food allergies develop is an area of much research. There appear to be multiple factors that contribute, such as genetics, timing of first exposure to a food, the diversity of bacteria in the gut, among others. The route of exposure does appear to play an important role.
For example, research has shown that initial exposure to a food allergen through the skin, especially in children with eczema, is more likely to lead to the development of allergy to that food (a process known as “sensitization”) than exposure to it by the mouth.
This may occur because the usual mechanisms of developing tolerance to a food when eaten are bypassed when the exposure happens first on the skin. Eczema also causes irritated skin, which may provide food allergens an easier entry point.
Whether food allergens in skin-care products can contribute to the development of food allergy is somewhat of an unknown. A U.K. study found an association between products containing crude peanut oil and the onset of peanut allergy among children with atopic dermatitis, especially those with active eczema rashes.
However, in the United States, skin-care products use highly refined oils, which contain almost no detectable allergen. It’s not known whether the use of these refined products is associated with risk of food allergy development. Given the uncertainty, many allergists will recommend against the use of skin-care products containing nut oils.
Dr. Sharma is an allergist, clinical researcher and associate professor of pediatrics. He is Chief of the Division of Allergy and Immunology at Children’s National Medical Center in Washington D.C. and Director of the Food Allergy Program. He co-authors “The Food Allergy Experts” column in Allergic Living magazine. Questions submitted will be considered for answer in the magazine.
Note: This column is meant as general guidance and is not to be interpreted as diagnosis and treatment of individual patient conditions. For specific medical advice, visit an allergist.Submit a Question View all posts by this medical expert.