2021 Volume 20 Issue 2 Pages 145-151
In this study, a patch test of skincare products (sunscreen and makeup cosmetics) containing metal materials and patch test reagents was performed to assess the causes of metal allergy for 30 patients examined at the Department of Dermatology in Shiga University of Medical Science between September 2018 and December 2019. We included patients in whom metal allergy was suspected from the manifestation of past symptoms. After 48 h of occlusive application, they were removed and judged according to the ICDRG (International Contact Dermatitis Research Group) criteria and the Japanese standard criteria for determining the patch test at 2h, 24 h, and 1 week after patch removal. Allergy was diagnosed when reactions were rated as“＋”(at over 24 h after patch removal) according to the ICDRG criteria. Moreover, the metallic species responsible for allergy was identified in approximately 16 out of 30 cases ; however, there were no allergic reactions to skincare products in any of the patients, including these 16 patients. There was no significant difference in the irritant response (irritation index) between 16 patients with metal allergy and 14 without metal allergy according to the Japanese standard criteria. In dermatology practice, it is necessary to confirm the existence of allergy and the causative metal for patients with metal allergy. Moreover, cosmetics contain metallic components for UV protection, skin protection, and coloring. Therefore, it is important to confirm the characteristics of the formulation, such as inhibition of metal ion release and surface coating, and then prescribe it according to the patient’s preference. Skin Research, 20 : 145-151, 2021
