Q. I have a soy allergy, and find that many personal care products, such as shampoos and body wash, contain soy. How concerned do I need to be about soy in these types of products?
Dr. Pistiner: Although oral ingestion is the most common and concerning form of exposure to an allergen, such as soy, skin contact is also of concern.
Some studies have shown that short-term exposure to an allergen on the skin does not cause severe allergic reactions. However, these studies (the allergen looked at was peanut) did show that 40 per cent of allergic subjects had localized skin reactions.
Allergens contained in skin products and cosmetics have been reported to cause allergic reactions. Most commonly these reactions are limited to the skin but systemic reactions have been reported, especially in those with a compromised skin barrier (i.e. eczema).
I would advise that avoiding products with soy is your safest option but please discuss your specific case with your healthcare provider prior to changing food allergy management strategies.
Dr. Michael Pistiner is an allergist in Massachusetts and clinical instructor at Children’s Hospital Boston, Harvard Medical School. He offers allergy teaching tools at Allergyhome.org .