FS06.1 Contact allergy to oxidized fragrance terpenes.

Terpenes are among the most widely used fragrances, found not only in fine fragrances but most often incorporated in domestic and occupational products. Terpenes oxidize easily at air‐exposure. Our previous studies have proved that limonene, linalool and caryophyllene are not allergenic in themselves but easily form allergenic products due to autoxidation. The aim of this study was to study the frequency and characteristics of allergic reactions in Europe to some oxidized fragrance terpenes. Method: Consecutive dermatitis patients in six European dermatological centers were patch tested with oxidized terpenes. Questionnaires, standard and additional fragrance patch test materials were used in the diagnosis of fragrance allergy. Results: Oxidized limonene was tested in 2411, while oxidized linalool, linalool hydroperoxide, oxidized caryophyllene, caryophyllene oxide and oxidized myrcene in additional 1511 patients. Of the patients tested 2.6% showed positive reaction to oxidized limonene, 1.3% to oxidized linalool, 0.5% to oxidized caryophyllene and 1 patient to oxidized myrcene. 1.1% of the patients reacted to linalool hydroperoxide, while testing with caryophyllene oxide resulted in few positive Results: 60% of the patients reacting to oxidized terpenes had fragrance related contact allergy and/or positive history for fragrance related dermatitis. Conclusion: Oxidized limonene and linalool are common allergens in dermatitis patients tested consecutively in Europe. Our results indicate that autoxidation of fragrance terpenes contributes to fragrance allergy to a great extent. This observation emphasises the need of testing with chemicals that patients actually come in contact with and not only ingredients that were originally applied in the commercial formulations.