Prevalence and Risk Factors of Occupational Contact Dermatitis to Formaldehyde and Glutaraldehyde and their Co-Reactivity in Dental Professionals

Background: In dental practice concomitant exposure to formaldehyde and glutaraldehyde is a common occurrence. The objective of the study is to evaluate the incidence of occupational contact dermatitis to formaldehyde and glutaraldehyde in dental professionals and the manifestation of co-reactivity. Methods and Results: This study involved 78 participants (30 dental professionals and 48 referents). A questionnaire survey as well as skin patch testing with formaldehyde and glutaraldehyde was conducted. The incidence of occupational contact dermatitis to formaldehyde among the population investigated was 28.2%, and of glutaraldehyde, 24.4%. Occupational contact dermatitis to formaldehyde was found to be of a significantly higher incidence among dental professionals. A stronger irritant effect of the formaldehyde, with a significantly higher incidence and the relative risk of specifically the upper respiratory tract (р = 0.029) and respiratory system (р = 0.002) as well as skin (р = 0.019) symptoms among the subjects experiencing formaldehyde contact dermatitis was demonstrated. Allergic predisposition plays an important role as a risk factor of sensitization to glutaraldehyde and of co-reactivity. Conclusions: The results indicate high rates of sensitization to formaldehyde and glutaraldehyde. Co-reactivity was found mainly among the non-occupationally exposed people. Atopy does not appear to be a risk factor for formaldehyde-specific allergic contact dermatitis, although it is so for glutaraldehyde-specific allergic contact dermatitis. Screening patch-testing for multiple dental compounds would be beneficial for early diagnosis, as well as for occupational risk assessment and management.