BACKGROUND: Contact dermatitis is typically an allergic reaction of the skin to some type of allergenic substance. The cause of the allergic response varies, but it sometimes involves free-radical reactions, suggesting that antioxidants may be beneficial for these types of reactions.
RESEARCH: Researchers exposed guinea pigs to a chemical known to cause contact allergic dermatitis through a free-radical reaction in the epidermis. Some of the animals were pretreated topically with a combination of vitamins E and C, either before initial sensitization to the allergen or after subsequent exposure to it. The researchers noted whether the antioxidants reduced the initial allergic reaction or the redness or swelling resulting from allergic reactions. The effects of antioxidants on allergic reactions that do not involve free radicals were also investigated.
RESULTS: Significantly fewer animals pretreated with a combination of vitamins E and C had reactions to the allergy-triggering chemical. For example, topical pretreatment with the antioxidant combination resulted in less than half of the animals becoming sensitized to the allergen, whereas nearly all of the untreated animals became sensitized to the allergen. Similarly, fewer sensitized animals reacted to the allergen when pretreated with the antioxidants. Antioxidant treatment had no effect on allergic reactions stimulated by non-free radical allergens such as metals or irritants.
IMPLICATIONS: The researchers wrote that "the protective effect of antioxidants...could be of practical therapeutic value." Topical antioxidants may be of benefit in allergic reactions that involve particular types of free radical reactions.
Gafvert E, Nilsson JLG, Hagelthorn G, et al., "Free radicals in antigen formation: reduction of contact allergic response to hydroperoxides by epidermal treatment with antioxidants," British Journal of Dermatology, 2002;146:649-656.
For the original abstract, visit: http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11966698&dopt=Abstract