Cinnamic aldehyde, alcohol cause reactions in patients allergic to fragrance

A prospective study has revealed that cinnamic aldehyde and cinnamic alcohol are the most common allergens that cause immediate and delayed reactions among patients with allergic contact dermatitis to fragrance. In addition, reactions to benzyl alcohol, sorbic acid, and coumarin are usually seen in immediate patch tests.

“Fragrance is one of the common causes of immediate contact reaction,” the researchers said. “Knowing the prevalence of a reaction in a given population enables prioritization of allergy screening.”

In this study, a group of researchers sought to determine the prevalence of an immediate patch test reaction to fragrance in patients with fragrance allergic contact dermatitis. A total of 291 participants were enrolled and given standard patch tests for allergic contact dermatitis.

Patients with positive reactions were then asked to have further patch tests to assess both immediate and delayed reactions to 28 different fragrance substances.

The most frequently encountered substances in positive immediate reactions and standard (delayed) patch test reactions were cinnamic aldehyde and cinnamic alcohol. On the other hand, immediate patch reactions to benzyl alcohol, sorbic acid, and coumarin were more commonly seen compared with standard patch test reactions.

“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,” the researchers said.