Burning Mouth Syndrome - American Family Physician

/Home/Burning Mouth Syndrome News and Information/Burning Mouth Syndrome Articles

Burning Mouth Syndrome
February 15, 2002
MIRIAM GRUSHKA, M.SC., D.D.S., PH.D., William Osler Health Center, Etobicoke Campus, Toronto, Ontario, and Yale University School of Medicine, New Haven, Connecticut
JOEL B. EPSTEIN, D.M.D., M.S.D., University of British Columbia, Vancouver, British Columbia, and University of Washington, Seattle, Washington
MEIR GORSKY, D.M.D., Tel Aviv University, Tel Aviv, Israel
American Family Physician
A peer-reviewed journal of the American Academy of Family Physicians
Burning mouth syndrome is characterized by a burning sensation in the tongue or other oral sites, usually in the absence of clinical and laboratory findings. Affected patients often present with multiple oral complaints, including burning, dryness and taste alterations. Burning mouth complaints are reported more often in women, especially after menopause. Typically, patients awaken without pain but note increasing symptoms through the day and into the evening. Conditions that have been reported in association with burning mouth syndrome include chronic anxiety or depression, various nutritional deficiencies, type 2 diabetes (formerly known as non¨?insulin-dependent diabetes) and changes in salivary function. However, these conditions have not been consistently linked with the syndrome, and their treatment has had little impact on burning mouth symptoms. Recent studies have pointed to dysfunction of several cranial nerves associated with taste sensation as a possible cause of burning mouth syndrome. Given in low dosages, benzodiazepines, tricyclic antidepressants or anticonvulsants may be effective in patients with burning mouth syndrome. Topical capsaicin has been used in some patients. (Am Fam Physician 2002;65:615-20,622. Copyright¨© 2002 American Academy of Family Physicians.)

Burning mouth syndrome has been defined as burning pain in the tongue or oral mucous membranes, usually without accompanying clinical and laboratory findings.1,2 In the past few years, some investigators have disputed this definition, arguing that it is too restrictive and suggesting that the syndrome may exist coincidentally with other oral conditions.3
There has also been no clear consensus on the etiology, pathogenesis or treatment of burning mouth syndrome.4 As a result, patients with inexplicable oral complaints are often referred from one health care professional to another without effective management. This situation not only adds to the health care burden of these complaints but also has a significant emotional impact on patients, who are sometimes suspected of imagining or exaggerating their symptoms.
Burning mouth pain is often absent during the night but progressively increases throughout the day and into the evening.

This article provides updated information on burning mouth syndrome and presents a new model, based on taste dysfunction, for its pathogenesis. Current treatment options are discussed, although data on the effectiveness of these treatments remain limited.
Epidemiology
Based on the makeup of most studies published to date, oral burning appears to be most prevalent in postmenopausal women.5 It has been reported in 10 to 40 percent of women presenting for treatment of menopausal symptoms.6 These percentages are in contrast to the much lower prevalence rates for oral burning in epidemiologic studies (0.7 to 2.6 percent).7 The reason for the gender difference between study populations (approximately 85 percent of study subjects have been women) and epidemiologic studies (which demonstrate a more equal distribution of oral burning in men and women) may be related to the definition used in each study design.
Pain Characteristics
In more than one half of patients with burning mouth syndrome, the onset of pain is spontaneous, with no identifiable precipitating factor. Approximately one third of patients relate time of onset to a dental procedure, recent illness or medication course (including antibiotic therapy). Regardless of the nature of pain onset, once the oral burning starts, it often persists for many years.8
The burning sensation often occurs in more than one oral site, with the anterior two thirds of the tongue, the anterior hard palate and the mucosa of the lower lip most frequently involved.5 Facial skin is not usually affected. No correlation has been noted between the oral sites that are affected and the course of the disorder or the response to treatment.

Damage to the cranial nerves that serve taste function is thought to decrease the inhibition of trigeminal-nerve pain fibers, which can lead to oral burning symptoms.


In many patients with the syndrome, pain is absent during the night but occurs at a mild to moderate level by middle to late morning. The burning may progressively increase throughout the day, reaching its greatest intensity by late afternoon and into early evening.8 Patients often report that the pain interferes with their ability to fall asleep. Perhaps because of sleep disturbances, constant pain, or both, patients with oral burning pain often have mood changes, including irritability, anxiety and depression.2 Earlier studies frequently minimized the pain of burning mouth syndrome, but more recent studies have reported that the pain ranges from moderate to severe and is similar in intensity to toothache pain.9
Little information is available on the natural course of burning mouth syndrome. Spontaneous partial recovery within six to seven years after onset has been reported in up to two thirds of patients, with recovery often preceded by a change from constant to episodic burning.5,10 No clinical factors predicting recovery have been noted.
Most studies have found that oral burning is frequently accompanied by other symptoms, including dry mouth and altered taste.5 Alterations in taste occur in as many as two thirds of patients and often include complaints of persistent tastes (bitter, metallic, or both) or changes in the intensity of taste perception. Dysgeusic tastes accompanying oral burning are often reduced by stimulation with food.5,8 In contrast, application of a topical anesthetic may increase oral burning while decreasing dysgeusic tastes.
Etiologic Factors
Because of a long-standing difficulty in understanding the pain of burning mouth syndrome and its complex clinical picture, a number of etiologies have been suggested. However, each of these postulated causes explains the pain in only small groups of patients. With the recently increased understanding of the role that taste damage plays in the pathogenesis of burning mouth syndrome, many of these etiologies can now be viewed as part of a larger model of disease.
Please visit the Web site to view the report in its entirety.