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.