Cosmetics and skin care products

Contact allergy to ingredients of cosmetics is one of the most frequent causes of contact allergy. While patients may report reactions to fragrance items, preservative allergy may not be suspected. The reaction typically resembles eczema on the face or hands, although any body site may be affected. Products left on the skin are much more likely to cause allergic reactions than rinse-off products. Common allergens include fragrances (e.g., hydroxyisohexyl-3-cyclohexene carboxaldehyde, isoeugenol, etc.), preservatives (e.g., formaldehyde and formaldehyde-releasers, MCI/MI, paraben esters, etc.); hair dye chemicals (e.g., p-phenylenediamine), and less frequent allergens such as lanolin and propylene glycol. Patch testing is mandatory where allergy is suspected or in localized/difficult-to-treat eczema. Sometimes a repeated open application test (ROAT) is required when the patch tests are surprisingly negative. Mandatory ingredient labeling of cosmetic items in the EU facilitates allergen avoidance and EU-set limits on the concentration of known allergens seem to be reducing the incidence of allergic contact dermatitis to certain preservatives. © 2011 Springer-Verlag Berlin Heidelberg.