Simultaneous patch testing with fragrance mix I, fragrance mix II and their ingredients in southern Sweden between 2009 and 2015

SummaryBackground Fragrance mix I (FM I) and fragrance mix II (FM II) are included in the European baseline series as screening substances for fragrance contact allergy. Objectives To investigate the frequency of allergic reactions to FM I, FM II and their ingredients in consecutively patch tested patients. Materials and methods A retrospective analysis of data from 4430 patients patch tested between 2009 and 2015 was performed. Results Of the patients, 6.5% were FM I-positive and 3.2% were FM II-positive. Forty-five per cent of FM I-positive patients did not have positive reactions to FM I ingredients. Thirty-five per cent of those who were FM II-positive did not have positive reactions to FM II ingredients. Twenty-seven per cent of those with positive reactions to one or more of the FM I ingredients were FM I-negative, and 36% of those who had positive reactions to one or more of the FM II ingredients were FM II-negative. The allergens with the highest pick-up rates were Evernia prunastri (1.8%), cinnamal (1.3%), citral (1.2%), and hydroxyisohexyl 3-cyclohexene carboxaldehyde (1.2%). Significant differences were observed in the proportions of positive reactions to FM I, FM II, eugenol, isoeugenol, and farnesol when results from patch testing with materials from different suppliers were compared. Conclusions There is a risk of missing fragrance contact allergy when testing with only the fragrance mixes is performed. The use of preparations from different suppliers may affect the patch test results.