Fragrance allergy: a chemical perspective for dermatologists

Sensitivity to fragrance ingredients is acknowledged as a common and clinically important problem in Europe.Aims of the project: The “fragrance chemical allergy” project (QLK4‐CT‐1999‐01558) funded by the European Commission under the Quality of Life programme was to increase the safety standard of fragrance compounds and provide more transparency in the data available, and to develop prevention of fragrance chemical allergy in non sensitised (primary prevention) and in already sensitised (secondary prevention) individuals.Primary prevention: A strategy for the rapid identification of sensitizers in complex mixture has been developed and 2 major sensitizers of oak moss, namely atranol and chloroatranol have been identified. Oxidation products, formed during storage and handling of common terpenes, have been shown to be involved in the sensitizing potential of fragrances. Quantitative Structure‐Activity Relationships have been developed for 2 classes of aldehydes often present as perfume ingredients. Major fragrance allergens relevant to hand eczema have been identified.Secondary prevention: A new fragrance mix “FMII” has been developed as a diagnostic tool for patients allergic to fragrances. An elicitation thresholds methodology has been established and validated with some important new sensitizers. The substitution strategy of sensitizing fragrance chemicals by analogues has been studied in the case of isoeugenol and demonstrated to be non relevant to consumer safety.Expected applications of results: Data generated by this project will be used as basis for decisions to improve consumer safety such as product labelling of the most frequent sensitizing materials, making guidelines for the evaluation of safe concentration limits, making rules of handling and best‐before‐date and banning of the most sensitizing compounds in consumer products.Participants: University Strasbourg (F), NIWL Stockholm (S), Unilever SEAC (UK), University Copenhagen (DK), University Witten/Herdecke (D), King’s College London (UK), NERI Roskilde (DK), University Odense (DK), University Malmö(S), University Leuven (B).