Patch test in Chinese in Shanghai with cosmetic allergy to cosmetic series and products

Background There are increasing cosmetic adverse reactions in China, mostly cosmetic contact dermatitis, with the development of its cosmetics industry. Aims To identify the allergens and cosmetics products responsible for cosmetic allergic contact dermatitis (CACD) in Shanghai. Methods Five hundred and sixty patients, including 342 suspected CACD patients from dermatological clinic and 218 cosmetics consumers with an allergic history, were patch tested with a cosmetic series (C‐1000 series). And 154 patients patched with possible culprit cosmetics. Results Two hundred and forty‐six subjects showed positive reaction to C‐1000 series. Clinic patients had much higher positive rate than that of cosmetics consumers. Leading allergens were methylisothiazolinone (MI), methylisothiazolinone + methylchloro‐isothiazolinone (MCI/MI), thimerosal, and the positive rates were significantly higher in patients than in cosmetic consumers (P