Fragrance- and Botanical-Related Allergy and Associated Concomitant Reactions: A Retrospective Analysis of the North American Contact Dermatitis Group Data 2007-2016

Importance: When fragrance- and botanical-related (F/BR) allergy is identified, concomitant reaction (CR) frequencies can help direct avoidance recommendations. Objective: This study aimed to determine the CR rates for F/BR allergens. Design: A retrospective cross-sectional analysis of the North American Contact Dermatitis Group data 2007-2016 was conducted. Frequencies of demographics, positive reactions, strength of reactions, trends, and CR rates were calculated. Results: A total of 5504 (22.7%) of 24,246 patients had F/BR allergic reactions. The F/BR-sensitive patients were more likely to be female, older than age 40 years, and White and have face, leg, or anal/genital dermatitis. Top allergens included fragrance mix I (FMI, 10.6%), Myroxylon pereirae (balsam of Peru [BOP], 8%), and fragrance mix II (FMII, 4.9%). There were increasing trends for FMI, FMII, cinnamic aldehyde, and Compositae mix and decreasing trends for BOP and propolis. When patients were positive to any F/BR allergen, they were likely to be positive to FMI, FMII, and BOP. Concomitant reactions were bidirectional between multiple fragrance allergens and propolis, colophony, and Compositae mix. Conclusions: Concomitant reactions were identified between fragrances, between fragrances and BR allergens, and between BR allergens and fragrances. If CRs of greater than 10% suggest cross-reactivity, then all patients with fragrance sensitivity should avoid BR allergens and vice versa.