Article

Formaldehyde (F) is a ubiquitous chemical agent, part of our working and residential environment. It is a well-known mucous membrane irritant and a skin sensitizing agent associated with contact dermatitis. The concomitant exposure to formaldehyde and glutaraldehyde is common in dental practice. The aim of the present study was to perform a comparative overall evaluation of the health status of subjects with formaldehyde and glutaraldehyde-specific allergic contact dermatitis, in occupational and non-occupational exposure. A detailed and intentionally conducted questionnaire survey was performed among a total of 78 participants: 30 dental professionals occupationally exposed to formaldehyde, and 48 non-exposed healthy subjects (referents). All participants were clinically assessed, including a review of medical summary of history and physical examination. Skin patch testing with formaldehyde and glutaraldehyde was performed and a possible co-reactivity was assessed. The general incidence of formaldehyde-specific allergic contact dermatitis was 28.2%, and of glutaraldehyde-specific allergic contact dermatitis, 24.4%. The results demonstrated a stronger irritant effects of formaldehyde compared to glutaraldehyde, expressed in significantly higher incidence and relative risk of subjective upper respiratory tract (р = 0,029, OR=3,049 {1,102-8,442}), respiratory system (р = 0,002, OR=4,916 {1,699-14,228}) and skin (р = 0,019, OR=3,314 {1,191-9,218}) symptoms among subjects with formaldehyde-specific contact dermatitis. The gender analysis showed a significantly higher frequency and relative risk for sensitization to formaldehyde among women (χ² = 4,371, p = 0.037, OR = 3,219 (1,053-9,838). Women with formaldehyde-specific allergic contact dermatitis seem to be a vulnerable group for clinical upper respiratory tract alterations. No increased incidence of upper respiratory tract infectious pathology among subjects with allergic contact dermatitis was established. Tobacco smoking seems to be a risk factor for sensitization to formaldehyde, but not to glutaraldehyde. Allergic predisposition is a risk factor for sensitization to glutaraldehyde, but not to formaldehyde. On other hand, its role for co-reactivity was categorically demonstrated. Studies of this kind, including patch-testing for more dental materials compounds, would be beneficial for early diagnosis of contact allergy, as well as risk assessment and management.