Recovery from mercury-induced burning mouth syndrome due to mercury allergy.

We report a case in which burning mouth syndrome (BMS) was associated with a strong allergy to mercury. The aim of this case history is to strengthen knowledge of the relationship among allergy to mercury, systemic allergic contact dermatitis, and hypersensitivity of the oral mucosa. We performed series of standard and dental patch tests for screening for contact allergy to dental materials, in accordance with International Contact Dermatitis Research Group guidelines. Positive extreme allergic reactions to mercury (+++) and amalgam (++) were seen at the patch site and caused a flare-up of the systemic erythematous reaction. Full recovery from BMS and complete remission of systemic dermatitis were achieved after the mercury tooth filling was removed. Mercury is thought to be an allergen implicated in BMS as well as in the systemic reactivation of allergic contact dermatitis. Patch testing with dental series seems to have greater sensitivity and relevance in BMS patients.