Importance of irritant contact dermatitis in occupational skin disease

Background: Irritant contact dermatitis (ICD), provoked by work materials or workflows, is believed to be a frequent cause of occupational skin disease (OSD). Data of incidence rates of ICD within different occupations are inadequate. Objective: We conducted a population-based study to identify occupational groups at risk for irritant and allergic contact dermatitis (ACD). Methods: The data are based on all workers' compensation claims reported to our register of OSDs in Northern Bavaria [Berufskrankheitenregister Haut-Nordbayern (BKH-N)], Germany. Results: From 1990 to 1999, 5285 patients had their cases completely assessed and recorded by government-employed physicians. We calculated the incidence rates of ICD and ACD in various occupations, divided into 24 occupational groups, in co-operation with the German State Institute of Labor and Occupation; there were a known total number of employees in each of the occupations. In these groups 3097 (59%) patients with OSD were observed, with an overall annual incidence rate of 4.5 patients per 10 000 workers for ICD, compared with 4.1 patients per 10 000 workers for ACD. The highest ICD annual incidence rates were found in hairdressers (46.9 per 10 000 workers per year), bakers (23.5 per 10 000 workers per year), and pastry cooks (16.9 per 10 000 workers per year); at the same time ICD was the main diagnosis of OSD in pastry cooks (76%), cooks (69%), food processing industry workers and butchers (63%), mechanics (60%), and locksmiths and automobile mechanics (59%). The results of a questionnaire showed frequent skin contact with detergents (52%), disinfectants (24%), and acidic and alkaline chemicals (24%) in the workplace. Conclusion: Based on the incidence data of the BKH-N, this study identified occupational groups with a high risk of ICD. Different frequencies of ICD and ACD within a single group are demonstrated. The frequent usage of detergents is being addressed because of the introduction of German legislation of recent date (the Approved Code of Practice 531 on 'wet work').