Dianne Burrows1, Marie-Claude Houle, D Linn Holness, Joel DeKoven, Sandy Skotnicki. 1. From the *Queen's University, Kingston; †Department of Occupational and Environmental Health, St Michael's Hospital, Toronto, Ontario; ‡Division of Dermatology, Department of Medicine, Hotel-Dieu de Québec, Université Laval, Québec City, Québec; §Dalla Lana School of Public Health, and ∥Department of Medicine, University of Toronto, Ontario, Canada.
Abstract
BACKGROUND: Patch testing with standard trays of commercially available allergens is the current practice for investigating suspected cases of isocyanate-induced allergic contact dermatitis (ACD). In some facilities, these standard trays are further supplemented with custom preparations of isocyanate-containing materials. OBJECTIVE: The aim was to determine whether added value exists in patch testing patients to custom isocyanate preparations in suspected cases of ACD. METHODS: We performed a retrospective analysis of 11 patients referred to our specialty clinic between January 2003 and March 2011 for suspected patients of ACD who had custom testing with isocyanate materials from their workplace. In addition to standard trays of allergens, all patients were patch tested with custom isocyanate materials from their workplaces. RESULTS: Three (27%) of 11 patients showed an added value in testing to custom isocyanate allergens. Of these 3 patients, one had a reaction that reinforced positive reactions to the standard isocyanate tray, but the other 2 (18%) had no reactions to any of the commercially available allergens. CONCLUSIONS: Because of the high proportion of reactions (27%), we recommend the use of custom testing to workplace isocyanate products as a supplement to current standard patch testing procedures.
BACKGROUND: Patch testing with standard trays of commercially available allergens is the current practice for investigating suspected cases of isocyanate-induced allergic contact dermatitis (ACD). In some facilities, these standard trays are further supplemented with custom preparations of isocyanate-containing materials. OBJECTIVE: The aim was to determine whether added value exists in patch testing patients to custom isocyanate preparations in suspected cases of ACD. METHODS: We performed a retrospective analysis of 11 patients referred to our specialty clinic between January 2003 and March 2011 for suspected patients of ACD who had custom testing with isocyanate materials from their workplace. In addition to standard trays of allergens, all patients were patch tested with custom isocyanate materials from their workplaces. RESULTS: Three (27%) of 11 patients showed an added value in testing to custom isocyanate allergens. Of these 3 patients, one had a reaction that reinforced positive reactions to the standard isocyanate tray, but the other 2 (18%) had no reactions to any of the commercially available allergens. CONCLUSIONS: Because of the high proportion of reactions (27%), we recommend the use of custom testing to workplace isocyanate products as a supplement to current standard patch testing procedures.