CARVONE - AN OVERLOOKED CONTACT ALLERGEN CROSS-REACTING WITH SESQUITERPENE LACTONES

The terpene l-carvone is one of the main constituents of spearmint oil . The sensitizing potential of l-carvone has been considered low, but it has occasionally caused contact allergy in users of spearmint tooth paste and chewing gum. l-Carvone is also an oxidation product of d-lim onene that occurs in solvents used increasingly in industry. We includ ed l-carvone 5% pet. in the standard patch test series. In the 1st yea r, 541 patients were tested and 15 (2.77%) had positive, and 12 doubtf ul positive (?+) reactions to l-carvone. The strongest reactions were observed in 9 patients with concomitant Compositae sensitivity. The ke y clinical features and other contact allergies of the patients are pr esented. When re-testing with l-carvone in the same or lower concentra tions, only 2 out of 8 patients had positive reactions. Possible reaso ns for this discrepancy are discussed in terms of cross-reactions, con comitant sensitization, excited skin syndrome, irritancy and facilitat ed immunological response.