Burning mouth syndrome (BMS) is defined as burning sensation in the mouth without any observable abnormalities.
Many people with BMS also describe oral dryness; some of these people with oral dryness have findings consistent with Sjogren's syndrome (a condition that classically causes dryness of the eyes and mouth). Because of this association we screen all of our BMS patients for Sjogren's and other conditions manifested by oral dryness.
Burning mouth patients, including those with Sjogren's, sometimes have an oral candidal (thrush) infection that is not readily apparent on examination. Because the treatment is benign (Nystatin vaginal troches slowly dissolved in the mouth, one troche four times a day), we recommend a two week treatment for possible candidiasis. (We use vaginal troches because there is no sugar in them and patients with dry mouth are prone to more cavities in their teeth if they use a sugar-containing troche). If the oral burning improves, we treat for an additional 6 weeks. Some patients require a full three months of treatment to eradicate the infection, especially if their mouths are dry. During treatment, it is important to disinfect any dentures simultaneously so that the infection is not reintroduced into the mouth. Your dentist will provide you with disinfectant recommendations for your dentures. Your doctor can obtain an oral candidal culture prior to treatment with Nystatin, but our recommendation is to treat regardless of culture results because we have seen improvement even when cultures are negative.
In addition to the above, we screen for nutritional deficiencies (B1, B2, B6, B12, folic acid and iron) and diabetes mellitus in all patients, because some of our patients have low vitamin and/or mineral test results, and elevated serum glucoses. Both nutritional deficiencies and diabetes have been reported to be associated with oral burning in other studies.
Lastly, if evaluation to this point is unrevealing, we suggest an MRI scan of the head, to make certain that there is nothing in the brain causing the burning sensations. For example it is possible that a small "stroke" in a specific area can cause oral burning symptoms.