Contact dermatitis and respiratory symptoms in the construction industry: The role of filaggrin gene variants

Background: A high prevalence of contact dermatitis and respiratory symptoms has been observed in the construction industry, probably due to widespread exposure to irritants and allergens. It is unknown if carriers of filaggrin ( FLG ) loss-of-function genetic variants, a known risk gene for eczema and asthma, are at increased risk. Aim: To investigate associations of FLG variants with occupational contact dermatitis (OCD) and respiratory symptoms in Dutch construction workers. Methods: A questionnaire including items on dermal and respiratory symptoms like wheeze, shortness of breath and asthma (adopted from the ECRHS questionnaire) was administered to construction workers. Total and specific serum IgE was analysed by enzyme immunoassays. Four FLG variants were genotyped. OCD was diagnosed by a team of a dermatologist and a clinical occupational medicine specialist using photographs of the subjects9 hands and questionnaire data. Results: Of the 506 participating workers, 6.3% carried at least one FLG variant. Mild symptoms of contact dermatitis were diagnosed by the specialists in 45.1%, severe symptoms in an additional 25.7%, and OCD was diagnosed in 56.7%. Carriers of FLG variants had an increased risk of severe symptoms and OCD compared to subjects carrying wild-type alleles (odds ratio (OR) severe symptoms: 5.83, 95% confidence interval (95% CI): 1.64-20.78; OR OCD: 4.34, 95% CI: 1.64-11.47). FLG variants and the presence of OCD were not associated with respiratory symptoms and atopy. Conclusion: OCD prevalence in construction workers is high. FLG loss-of function variants increase the risk of OCD even further. FLG variants were not associated with respiratory symptoms.