Abstract: Purpose:To find out the mechanism of cosmetic-related dermatitis.Methods:3 perfumes commonly used in cosmetics were selected (isoeugenol,cinnamic aldehyde and hydroxycitronellal) for laboratory studies of acute skin irritation test (ASIT),multi-irritation skin test (MIST),skin sensitization test (GPMT) and percutaneous penetration in vitro in experimental animals were performed respectively.Results:ASIT showed that none of the three chemicals was irritative.MIST revealed that cinnamic aldehyde was an irritant,and the others were not,the average index of skin irritation was consistent with the severity of histopathologic changes.GPMT showed all of the three chemicals were strong sensitizers.Percutaneous penetration of three kinds of perfumes in vitro showed all of them could be absorbed more or less,and the amount,rate and velocity of penetration of cinnamic aldehyde were the highest among them.Conclusion:The mechanism of cosmetic related dermatitis may be due to primary irritation and/or allergy.The potency of skin sensitization of a chemical is related to its percutaneous penetration.

Key words: Irritation, Sensitization, Percutaneous penetration, Perfume