[Allergic disease caused by squaric acid dibutyl ester: description of 2 cases in a work environment]

The paper describes an episode of contact dermatitis in 4 pharmaceutical industry workers. Symptoms regressed after cessation of exposure. Each worker underwent clinical investigations with specific patch tests for the products handled. In 2 subjects there were positive skin reactions to squaric acid dibutyl-ester, a substance with powerful allergenic action and consequently rarely used on the market. Following elimination of the compound from the production cycle, no further cases of dermal symptoms were reported among the operators.