Electrogalvanically-induced contact allergy of the oral mucosa. Report of a case.

A 69-year-old white female presented bilateral lesions of the oral mucosa possibly related to electrogalvanism. The lesions were histologically characterized as lichen planus and as mild epithelial dysplasia on the left and right sides, respectively. They disappeared after removing amalgam restorations opposing the lesions. Epicutaneous patch tests and lymphocyte-transformation tests showed that the patient suffered from a contact allergy to mercury compounds, indicating this as a mechanism by which electrogalvanism may induce lesions of the oral mucosa.