Allergic Contact Dermatitis — SCE Dermatology MCQ

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HardInflammatory DermatosesAllergic Contact DermatitisSCE Dermatology

A 44-year-old woman presents with a dermatitis affecting areas of skin where her perfume is applied (behind ears and wrists). Patch testing with the European baseline series is performed. A positive reaction to fragrance mix I is found. What is the commonest individual fragrance allergen within this mix?

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Correct answer: E — Oak moss absolute

This is allergic contact dermatitis to perfume, and a positive European baseline series reaction to fragrance mix I indicates sensitisation to one or more of its constituent fragrance allergens. Fragrance mix I contains cinnamal (cinnamic aldehyde), cinnamyl alcohol, hydroxycitronellal, amyl cinnamal, geraniol, eugenol, isoeugenol and Evernia prunastri (oak moss absolute). On breakdown testing of fragrance mix I, oak moss absolute is the individual constituent most often responsible for positive reactions; therefore the commonest individual allergen in this mix is oak moss absolute. The other listed options are fragrance mix I constituents but are less commonly the culprit.

Reference: Uter W, et al. Patch Test Results With the European Baseline Series, 2021/2022—Joint European Results of the ESSCA and EBS Working Groups of the ESCD, and GEIDAC. Contact Dermatitis, 2026. https://doi.org/10.1111/cod.70134