Fragrances are regarded as the most common contact allergens after nickel. In this context, the frequency of positive patch test reactions to fragrance mix is often presented as proof. According to EU regulation No. 1223/2009, 26 fragrances that are regarded as significant allergens have to be declared on cosmetic products.
The frequency of patch test reactions to fragrances and differentiation between frequently and rarely sensitizing fragrances were evaluated.
Data from the Information Network of Departments of Dermatology (IVDK), mostly of the years 2016-2018, were retrospectively analyzed.
Frequency of positive reactions to fragrance mix I in the departments of dermatology joining the IVDK reached a historical low of 5.4% in 2018. Since 2013, positive reactions to fragrance mix II have been declining, yielding 3.2% in 2018. Of fragrance mix I, the allergen with the most positive test reactions is no longer oakmoss absolute, but isoeugenol. In fragrance mix II, hydroxyisohexyl 3‑cyclohexene carboxaldehyde (HICC) is still leading. Only 11 of the 26 fragrances subject to mandatory declaration elicited allergic test reactions in more than 1% of the patients tested.
The decline of positive test reactions to the fragrance mixes is mainly due to the reduced use of oakmoss containing atranol and chloroatranol, and HICC. Use of these substances in cosmetic products was prohibited within the EU starting in August 2019. Therefore, a further decline of the sensitization frequencies can be expected. A differentiated consideration of the individual fragrances under allergological aspects is urgently required.