Non-fragrance allergens in specific cosmetic products.

Reports about the nature of the ingredients responsible for allergic contact dermatitis caused by specific cosmetic products are scarce. Between January 2000 and December 2010, the specific cosmetic products having caused allergic contact dermatitis, as well as the individual allergenic cosmetic ingredients present in them, were recorded by use of a standardized form. Among 11 different categories of cosmetic product, skin care products, followed by hair care and body-cleansing products, were most often involved. The presence of the allergenic ingredient(s) in a specific cosmetic product was confirmed according to the ingredient label in 959 of 1448 records. Six hundred and twenty-one of 959 concerned non-fragrance components, preservatives being responsible for 58% of them. Reactions to formaldehyde and formaldehyde-releasers were most often correlated with body-cleansing products, particularly 2-bromo-2-nitropropane-1,3-diol and skin care products. They were followed by the methylchloroisothiazolinone/methylisothiazolinone mixture, most frequently found as allergens in hair care and intimate hygiene products, and facial cleansers (in the last category together with diazolidinyl urea). Octocrylene was by far the most frequent (photo)allergen in sun care products. This study provides information on the presence and frequency of allergens in specific causal cosmetic products.