[Patch test of mercury compounds and disinfectant solutions and the clinical picture of mercury contact dermatitis].

The results of patch tests with mercury compounds and disinfectant solutions as well as the clinical picture of mercury contact dermatitis are presented and discussed. During the period from Nov. 1983 to Dec. 1986, 686 patients were tested with mercury compounds. During the 13 year period from 1974-1986, 118 patients were tested with disinfectant solutions and 59 patients with mercury contact dermatitis were seen. Among the disinfectant solutions tested, the highest incidence of positive reaction, 11.5%, was obtained with thimersal. Cross sensitization has been shown between mercurochrome and ammoniated mercury, but no statistical correlation existed that demonstrated cross sensitization between mercury and thimerosal until our study. Therefore, the allergen in mercurochrome contact dermatitis is mercury. No statistical correlation could be established between the occurrence of atopic dermatitis and the patch test reactions to mercury compounds. The contactants were mercurochrome, thimerosal, and broken thermometers in 49 out of 59 cases of mercury contact dermatitis. Consequently, the number of occurrence of mercury dermatitis can be reduced by the elimination of the use of these two disinfectant solutions and the substitution of electric thermometers for mercury thermometers.