A study of patch test results with 20 fragrance antigens

Background: The TRUE test and Korean standard series are frequently used to determine the cause of allergic contact dermatitis. Although the TRUE test and Korean standard series have some fragrance antigens, they do not include all Korean Food & Drug Administration (KFDA) labeled fragrances. Moreover, there is no report regarding the patch test result of the KFDA-labeled fragrances in Korea. Objective: This study aimed to investigate the prevalence of positive patch test reactions to the KFDA-labeled fragrances and compare the results of the TRUE test or Korean standard series. Methods: The patch test was conducted on patients with suspected allergic contact dermatitis due to fragrances or cosmetics. The fragrance ingredients patch test comprised 20 KFDA-labeled fragrance antigens including fragrance mix (FM)1, FM2, etc. We reviewed the clinical information of patients using the MOAHLFA index. Results: Of 237 patch-tested patients, 21 (8.9%) showed at least 1 positive reaction and 13 (5.5%) showed 2 or more positive reactions. The characteristics of the MOAHLFA index were not related to fragrance allergy. Eleven (4.5%) revealed a disagreement in the patch tests of FM and FM1 ingredients. Of 21 patients with fragrance allergy, 3 (14.3%) reacted solely to FM2. Cinnamyl alcohol and cinnamyl were the most common fragrance allergens. Conclusion: If the TRUE test or Korean standard series is solely employed to determine fragrance allergy, false negative cases and patients with contact allergy to fragrance ingredients not included in the FM1 fragrance can be missed. Therefore, it would be desirable to test the FM and fragrance ingredient antigens simultaneously.