Perfumes are the most important cosmetic allergens. In cases of presumed allergy to a perfumed product, the allergy workup depends essentially on patch tests. Today, we have several markers available in the standard European battery: Fragrance mix I, Fragrance mix II, Peru balsam, rosin and Iyral. To these are added the 26 strongest sensitizing perfume molecules which have been identified by the European Directive of 2005. However, due to the complexity of the formulations, all the allergic reactions to perfumes cannot be identified, which necessitates flew, non-invasive methods of examination. (C) 2009 Elsevier Masson SAS. All rights reserved.