An epidemic of occupational contact dermatitis from an immersion oil for microscopy in laboratory personnel

Since November 1997, 14 successive cases of occupational contact dermatitis were observed in 13 laboratory technicians and 1 physician, working in a g enetics laboratory in Leuven (Belgium) in 3 laboratories of bacteriology in Strasbourg, Montbeliard and Angers, and in the laboratory of hematology in Bordeaux (France). The dermatitis, located on the hands, forearms and face , relapsed after each exposure to an immersion oil for microscopy. Patch te sts performed in 10 patients were positive to epoxy resin (ER) in the Europ ean standard series (10/10 patients) and to newly formulated Leica(R) immer sion oil (7/7), 1 patient testing negatively with the former oil. A breakdo wn performed in 2 patients with the oil's ingredients confirmed sensitizati on to liquid modified ER components, contained at >80% concentration in the oil. The presence of DGEBA was demonstrated by HPLC analysis at a +/-30% r ate. Although the safety data sheet indicated a revision of the formula, no body was alerted to the risk of sensitization and the need for skin protect ion. ERs, as a source of occupational allergy, can provoke epidemics of con tact dermatitis in industry. This report of epidemic contact dermatitis fro m ERs, used for their optical properties in an immersion oil for microscopy , emphasizes the need for perpetual vigilance in occupational medicine and the usefulness of multicentre contacts in dermato-allergology.