Background: Cosmetics have been used since the oldest known civilisations, and nowadays almost everybody resorts to beauty products. Objective: Considering the increasing incidence of contact dermatitis, the aim of the study is to determine the impact of allergy to cosmetics. Methods: From January 1998 to December 1999, 819 patients were subjected to epicutaneous tests for suspicion of allergic contact dermatitis (ACD). The results were analysed retrospectively in the total population and in that of children under 16: the interest has been focused on cosmetics. Results: 297 patients (36.3%) with ACD to 1 or more cosmetic ingredients have been detected. 34 (48.6%) out of 70 children patch tested showed an ACD: cosmetics represented the first cause. Conclusion: For two decades, the incidence of ACD has been rising; two main reasons can be put forward: a rising product consumption and a more exhaustive allergen research in patch testing.