Results of patch testing with fragrance mix 1, fragrance mix 2, and their ingredients, and Myroxylon pereirae and colophonium, over a 21‐year period

Background. The frequency of fragrance contact allergy has shown a fluctuating trend over the years. Objectives. To describe the frequency of positive reactions to the baseline screening agents and fragrance mix (FM) 1 and 2 components, to determine trends of the latter over the years, and to evaluate simultaneous reactions. Patients and methods This was a cross‐sectional study on patch test results of 13 332 patients from January 1990 to December 2011. Results. Of the total population, 9.6% reacted positively to FM 1, and 6% of 3416 tested with FM 2 reacted positively. Of those tested with both, 30.4% of 349 FM 1‐positive patients reacted to FM 2, and 51.7% of 205 FM 2‐positive patients reacted to FM 1. Hydroxyisohexyl 3‐cyclohexene carboxaldehyde (HICC) and FM 2 were tested simultaneously in 3401 patients: 6 reacted to HICC alone. Nine hundred and forty patients were tested with FM 1 ingredients and 205 with FM 2 ingredients; Evernia prunastri was the most frequent FM 1 allergen, and HICC was the most frequent FM 2 allergen. Simultaneous reactions were frequently observed. Conclusions. Fragrance‐allergic subjects often show multiple positive reactions, some of which are highly significantly associated. Recently, there has been a decreasing trend in positivity for both Evernia prunastri and HICC, whereas a slight increase for cinnamyl alcohol has been observed.