Abstract: 【Abstract】 Objective To analyze clinical characteristics of cosmetics-related adverse reactions and main allergenic components of cosmetics, to provide guidance for cosmetics-related adverse reaction monitoring, and to provide an objective basis for risk assessment. Methods A total of 512 patients with suspected cosmetic adverse reactions were collected from the outpatient clinic of Chongqing Traditional Chinese Medicine Hospital from March 2018 to October 2019, including 14 males and 498 females. A uniform cosmetic adverse reaction report card was filled in, and medical history of patients and related information about the used cosmetics were recorded; 103 patients （3 males and 100 females） were subjected to patch test with their own cosmetics or cosmetic ingredients, and 48- and 72-hour patch test results were combined for comprehensive determination and analysis. Results Among the 512 cases of suspected cosmetic adverse reactions, contact dermatitis （495 cases, 96.7%) was the most common manifestation. Cosmetic adverse reactions mainly manifested as erythema （501 cases, 97.9%）, papules （313, 61.1%）, edema （249, 48.6%）, and scaling （166, 32.4%）; main symptoms included itching （480,93.8%）, burning sensation （359, 70.1%）, and tense sensation （297, 58.0%）. Patch test with cosmetic ingredients showed positive reactions in 71 of 103 cases, and thimerosal was the allergen mostly liable to cause adverse reactions （31 cases, 30.1%）, followed by sodium dodecyl sulfate （29 cases, 28.2%）, Peru balsam （17 cases, 16.5%）, bronopol （12 cases, 11.7%） and triethanoamine （10 cases, 9.7%）. The cosmetic allergens were divided into 14 categories, and the top 4 categories with high positive patch test rates were emulsifiers （54 cases, 45.8%）, preservatives （47 cases, 39.8%）, fragrances （17 cases, 14.4%） and surfactants （10 cases, 8.5%）. Positive patch test reactions were observed in 2 males and 69 females, and there was no significant difference in the positive rate between males and females （2/3 vs. 69/100, χ2 = 0.01, P > 0.05）; there was also no significant difference in the positive rate among the groups aged 18 - 29 years （34%）, 30 - 49 years （34%） and 50 - 70 years （32.4%; χ2 = 0.693, P > 0.05）. Conclusions Contact dermatitis is the most common adverse reaction to cosmetics. Among the diverse allergenic components of cosmetics, thimerosal is the allergen that is mostly liable to cause adverse reactions, followed by sodium dodecyl sulfate, Peru balsam, bronopol and triethanoamine.

Key words: Cosmetics, Allergens, Adverse reactions, Patch test