Contact urticaria and protein contact dermatitis in the Finnish Register of Occupational Diseases in a period of 12 years

Background Although occupational contact urticaria (CU) and protein contact dermatitis (PCD) are considered frequent among workers with exposure to proteinaceous materials, data on occupations at risk and the main causes of these occupational skin diseases are relatively limited. Objectives To report the causative agents and risk occupations for CU and PCD in the Finnish Register of Occupational Diseases (FROD). Methods We retrieved from the FROD all recognized cases of CU/PCD in the years 2005-2016. Results With 570 cases, CU and PCD constituted 11% of all recognized cases of occupational skin diseases in the study period. Occupations with the highest incidence of CU/PCD included bakers, chefs and cooks, farmers and farm workers, veterinarians, gardeners, and hairdressers. The most common causative agents were cow dander and flour and grain, followed by natural rubber latex (NRL) and other food. In food-related occupations, wheat and other flours were by far the most common cause of CU/PCD, with 76 cases, whereas fish and other animal-derived food caused 33 and other plant-derived food caused 23 cases. Conclusions Apart from the Finnish peculiarity of cow dander allergy, a striking finding was a large share of CU/PCD caused by flours in food handlers as compared to other food.