Contact Dermatitis in the Construction Industry

Abstract

Construction workers are employed in a large and dynamic occupational sector and are exposed to hazardous substances during their work. This may cause diseases like contact dermatitis, one of the most prevalent occupational diseases in many countries. This thesis aims to assess the current prevalence and to discover risk factors of contact dermatitis in Dutch construction workers. The ultimate goal is to develop a prognostic tool for occupational physicians to detect contact dermatitis in an early, preferably preclinical, stage. Both self-reported and doctor-diagnosed prevalence of contact dermatitis among Dutch construction workers is high. The self-reported prevalence for (possible) contact dermatitis was 33%. A dermatological expert panel diagnosed mild contact dermatitis in 38% and severe contact dermatitis in an additional 23% of 751 investigated construction workers. Almost all cases of contact dermatitis were considered work-related (95%). Agreement between two occupational physicians and the expert panel’s diagnoses was low but increased after a dermatological training. Carriage of loss-of-function mutations in the filaggrin gene (FLG) is a well-studied endogenous risk factor for contact dermatitis. The risk of contact dermatitis was increased in carriers of at least one FLG variant (odds ratio (OR) mild contact dermatitis: 5.71, 95% confidence interval (CI): 1.63-20.06; OR severe contact dermatitis: 8.26, 95% CI: 2.32-29.39). Despite the strong associations, the attributable fraction for contact dermatitis of the four FLG loss-of-function mutations was only 8.5%. A limited number of occupational determinants were associated with contact dermatitis: washing the hands with solvents (PR (Prevalence Ratio): 1.17, 95% CI: 1.03-1.34), performing job-related tasks at home (PR: 1.14, 95% CI: 1.04-1.26), and self-reported difficulties with cleaning the hands at the end of the working day (PR: 1.13, 95% CI: 1.04-1.24). The lack of specific occupational determinants (e.g. materials like cement) and the fact that performing job-related tasks at home and difficulties with cleaning the hands at the end of the working day were significant determinants, might indicate that cumulative exposure to irritants is a key factor in the development of contact dermatitis in construction workers.A strong relation was found between loss-of-function mutations in the filaggrin gene and contact dermatitis, but the attributable fraction was relatively small. Moreover, ethical and practical issues preclude implementation of genetic testing in occupational health care. Based on the high contact dermatitis prevalence and the low agreement between the diagnoses of the occupational physicians and those of the dermatological expert panel, we conclude that occupational health care fails to successfully detect (early) contact dermatitis. We recommend that awareness of the risk to develop contact dermatitis in the construction industry should be increased, among occupational physicians as well as among employers and employees. In the ideal situation, as early as during their vocational training, construction workers should become familiar with the risk of skin problems and methods to prevent development of contact dermatitis.