Oral metal contact allergy: a pilot study on the cause of oral squamous cell carcinoma

Background Intraoral metal contact allergy may result in mucositis that mimics lichen planus and the pathogenesis of squamous cell carcinoma. Methods Clinical records of all patients examined in the departments of dermatology and otorhinolaryngology at a tertiary-care academic medical center between June 1994 and June 2000 who had a diagnosis of intraoral squamous cell carcinoma adjacent to a metal dental restoration and who were patch tested with our metal series were reviewed retrospectively. Eleven patients met the inclusion criteria. Results Ten patients (91%) had positive patch tests to metals. In eight (73%), the oral cancer was adjacent to a dental restoration containing a metal to which the patient was allergic. Prevalence of gold, mercury, silver, and copper allergy among these patients was substantially higher than that reported in the available worldwide patch-test clinic population. Conclusion Contact allergy to metal dental restorations may be a risk factor for development of intraoral squamous cell carcinoma.