Occupational contact dermatitis to propacetamol -: Allergological and chemical investigations in two new cases

Background and Objective: In 2 new cases of occupational contact dermatitis due to a recently described allergen (propacetamol), a prodrug which is a soluble diethylglycidyl ester of paracetamol, an allergological investigation was performed to elucidate the nature of the allergen involved in the propacetamol contact sensitivity. Observations: Two nurses with eczema of the hands and face had positive patch tests to Pro-Dafalgan(R). Every day the nurses prepared injections of Pro-Dafalgan(R) (propacetamol dissolved in sodium citrate). The sensitization was due to propacetamol and not to the solvent, To elucidate which part of propacetamol was responsible for the sensitization, the 2 nurses were patch-tested with diethylamine, paracetamol (diluted in different vehicles) and some of their chemical analogues and potential impurities which were all negative. Conclusions: Propacetamol induces airborne contact dermatitis with no evidence of sensitization to paracetamol or diethylglycine, possibly because of either the presence of unknown impurities and/or an antigenic structure related to the covalent bond of the prodrug.