Nine hundred building trade workers and 4372 office workers (from a database of 16267 patients) with suspected allergic dermatitis, underwent patch tests. The associations between patch test results and occupations were assessed by multivariate logistic regression analysis. As expected, building trade work was significantly associated with chromium sensitization (OR 1.55; 95% IC 1.22-1.97), a well known occupational hapten in this occupational group. An increased risk for epoxy resin sensitization (OR 3.80; 95% IC 2.11-6.86) and thiuram mix sensitization (OR 1.69; 95% IC 1.07-2.65) was also found in the construction workers. Epoxy resin is a strong skin sensitizer widely used in building trade, while thiuram mix is often present as an additive in the rubber gloves used by construction workers. These findings suggest that effective measures to prevent allergic contact dermatitis are needed in the construction workers.