The immediate patch test reaction to fragrance in patients with allergic contact dermatitis to fragrance: A prospective study

Background: Fragrance is one of the common causes of immediate contact reaction. Knowing the prevalence of a reaction in a given population enables prioritization of allergy screening. Objective: The purpose of this study was to determine the prevalence of an immediate patch test reaction to fragrance in patients with fragrance allergic contact dermatitis. Methods: This prospective study enrolled 291 patients who were given standard patch tests for allergic contact dermatitis. Those with positive reactions were then asked to undergo additional patch tests to assess both immediate and delayed reactions to 28 different fragrance substances. Results: Cinnamic aldehyde and cinnamic alcohol were the most frequently encountered substances in positive immediate reactions and standard (delayed) patch test reactions. Immediate patch reactions to benzyl alcohol, sorbic acid, and coumarin were more frequently observed than standard patch test reactions. Limitations: Because of the small sample size of patients who agreed to continue further patch testing evaluation, a statistical association between patient characteristics and fragrance-positive patch test reactions was difficult to establish. Conclusions: In this population, cinnamic aldehyde and cinnamic alcohol were the most common fragrance allergens causing both immediate and delayed reactions, whereas reactions to benzyl alcohol, sorbic acid, and coumarin were frequently observed in immediate patch tests.