The rôle of contact
allergens and aeroallergens in facial
dermatitis (FD) was studied. 114 cases of FD were divided into 3 groups. Group 1 comprised 47 cases of facial cosmetic
dermatitis (FCD), in which all patients had a history of
dermatitis related to
cosmetics clinically; group 2 comprised 15 cases of seasonal facial
dermatitis (SFD); Group 3 comprised 52 cases of other FD (OFD) that could not be categorized as FCD or SFD. Reactions to contact
allergens and aeroallergens were detected using patch testing and intradermal testing, respectively, with non-facial
eczematous skin disease patients serving as controls. The positivity rate for each
allergen between different groups was compared by the chi2-test. The results show that the positivity rate for fragrance mix in FCD is much higher than in non-FCD (27.7% versus 6.7% in SFD, 7.6% in OFD and 6% in
eczema patients, p<0.05). No significant difference was detected for other common
allergens, such as
PPD, rubber mix,
nickel sulfate, and
colophonium (p>0.05 for all). These results suggest that fragrance mix contains the main contact
allergens in FCD. Patch testing with patients' own products also yields high numbers of relevant results in FCD and OFD. No relevant patch test results were found in SFD, indicating that contact
allergy may not be relevant to SFD. No significant difference was observed between intradermal skin reactions to aeroallergens, including pollens and moulds, in SFD, OFD, FCD and controls. These results suggest that Type I reactions to aeroallergens may not be relevant in FD. The rôle of aeroallergens in FD needs to be studied further.