Prevalence, concomitant reactions, and factors associated with fragrance allergy in Thailand

Abstract

Background: Fragrances are the most common cause of cosmetic contact allergy. Up-to-date information on contact allergy frequencies and relevance aids primary and secondary preventive measures. Objectives: To determine the prevalence, associated factors, and concomitant reactions in fragrance allergy among Thais. Methods: This retrospective study collected data from 2012 to 2019. The patient characteristics of fragrance and nonfragrance allergy groups were compared. Concurrent positive reactions to fragrance allergens (fragrance mix [FM] I, FM II, Myroxylon pereirae resin and hydroxyisohexyl 3-cyclohexene carboxaldehyde) and other baseline-series allergens were analysed. Results: Of 1032 patients, 175 (17.0%) had fragrance allergy, with 57.7% of clinical relevance. FM I showed the highest prevalence (9.4%). The associated factors were being elderly, lesions on the extremities, metal allergy history, and long dermatitis duration. Contact allergies to epoxy resin and Compositae plants were significantly associated with fragrance allergy with an odds ratio of 5.95 (95% confidence interval [CI]: 5.21-6.80) and an odds ratio of 4.42 (95% CI: 1.58-12.36), respectively. No significant associations between colophonium (previously proposed as a fragrance marker) and fragrance allergens were found. Conclusions: The prevalence of fragrance contact allergy remains high and should be considered in old patients presenting with long-standing eczema on the extremities. Unlike reports from other countries, varied, significant, concomitant reactions were observed.