Burning Mouth Syndrome

Patan Gultawatvichai, M.D.

Basic Information

Definition

Burning mouth syndrome (BMS) is characterized by continuous burning pain in the tongue or oral mucous membranes where no underlying dental or medical cause can be identified and no oral signs are found. BMS may be accompanied by subjective xerostomia (dry mouth sensation in which no cause can be found), dysgeusia (altered taste), dysosmia (altered smell), and oral paresthesia (e.g., tingling).

Diagnostic criteria:

A.

Oral pain fulfilling criteria B and C
B.

Recurring daily for >2 hours per day for >3 months
C.
Pain has both of the following characteristics:
1. 1.
  
  Burning quality
2. 2.
  
  Felt superficially in the oral mucosa
D.

Oral mucosa is of normal appearance, and clinical examination including sensory testing is normal.
E.

Not better accounted for by another ICHD-3 (The international classification of headache disorders) diagnosis

Synonyms

BMS
Glossodynia
Oral dysesthesia
Glossopyrosis
Stomatodynia

ICD-10CM CODES
K14.6	Glossodynia

Epidemiology & Demographics

•

5 per 100,000 general population.
•

Women 3 to 7 times more likely than men of a similar age; most prevalent in postmenopausal women.
•

Typically occurs in middle-aged or older adults. The prevalence may increase from 3- to 12-fold with increasing age.
•

Asian and Native Americans have considerably higher risk.
•

30% to 50% of patients improve spontaneously.

Physical Findings & Clinical Presentation

•

Sensation is usually bilaterally located on the tongue, most frequently on the anterior two thirds of the tongue, the anterior hard palate, and the lower lip mucosa.
•

Sensation most typically described as burning, scalded, or tingling. Sometimes described as “discomfort,” “tender,” or “annoying” rather than pain or burning.
•

The oropharyngeal exam may show atrophy, erythema, leukoplakia, erosion, or ulceration.
•

May present with oral parafunctional habits such as bruxism, jaw clenching, and tongue thrusting, which are increased with anxiety.
•

Pain is chronic and often lasts at least 4 to 6 months.
•

Up to two thirds of patients report a spontaneous partial recovery within 6 to 7 years from onset, with the pain changing from constant to intermittent.

Etiology

More than 50% of cases have no identifiable cause (primary BMS). Many of the currently proposed etiologies of secondary BMS include:

•

Psychological dysfunction: Many patients concomitantly have personality or mood changes, report more adverse life events, somatization, anxiety, and depression. A proportion of patients have anxiety centered around concerns of cancer (cancerphobia).
•

Endocrine: Hormonal alterations in oral mucosa have been suggested as a cause, especially in menopause.
•

Immunologic: Observational studies have shown elevation of serum erythrocyte sedimentation (ESR) rate and salivary immunoglobulin A compared with control patients.
•

Infectious: Fusospirochetes, Candida, Enterobacter, Helicobacter pylori, and Klebsiella infection. Candida may not always produce visible lesions.
•

Local irritants, such as smoking, and dental materials, such as mercury.
•

Medications, such as angiotensin-converting enzyme (ACE) inhibitors and protease inhibitors.
•

Nerve damage.
•

Nutritional deficiencies: iron, zinc, folate, and vitamin B.

There may be an association between supertasters (those with enhanced ability to taste) and those with BMS caused by their increased density of taste buds that are surrounded by bundles of trigeminal nerve neurons.

Diagnosis

Differential Diagnosis

•

Mucosal disease such as lichen planus or candidiasis
•

Nutritional deficiency in zinc, iron, folate, or vitamins B₁, B₂, B₆, B₉, B₁₂
•

Dry mouth from Sjögren’s syndrome or after chemo/radiation therapy
•

Cranial nerve injury
•

Medication effect

Workup

•

Clinical history is the most important in diagnosing BMS.
•

Very important to rule out other pathologic conditions first.

Laboratory Tests

There is no diagnostic test for BMS but consider testing for vitamin B, folate, ferritin, or zinc deficiency as well as CBC, luteinizing hormone, follicle-stimulating hormone, and ESR.

Treatment

Nonpharmacologic Therapy

Consider discontinuation of medications that may cause xerostomia (e.g., anticholinergics, psychotropics) and substitution for medications that may cause oral burning (e.g., ACE inhibitors, angiotensin-receptor blockers, antiretrovirals). Formal psychotherapy and cognitive behavioral therapy have been helpful for some patients.

Capsaicin (hot pepper powder) can be used as a topical desensitizing agent.

•

Rinse mouth with 1 tsp of a 1:2 solution of hot pepper and water; increase strength of capsaicin as tolerated to a maximum 1:1 dilution.

Acute General Rx

No definitive cure exists. Attempting combinations of therapies may be appropriate. Interestingly, cognitive therapy may be synergistic with other agents.

Treatment options currently include:

•
Low-dose benzodiazepines:
1. 1.
  
  Clonazepam 0.25 to 2 mg/day; start with 0.25 mg at bedtime and increase dose q 4 to 7 days until oral burning is relieved or side effects.
2. 2.
  
  Topical clonazepam solution 0.1 to 0.5 mg/ml; swish with 5 ml for 5 minutes and spit two to four times daily.
•
Low-dose tricyclic antidepressants:
1. 1.
  
  Amitriptyline or nortriptyline 10 to 150 mg/day; start with 10 mg at bedtime and increase dose by 10 mg q 4 to 7 days.
•
Low-dose gabapentin 300 to 1600 mg/day; start with 100 mg at bedtime and increase dose by 100 mg q 4 to 7 days (take in divided doses).
1. 1.
  
  Oral nystatin
•

Capsaicin (topical oral)

Complementary & Alternative Medicine

•

Antioxidant alpha lipoic acid
•

Acupuncture may be effective
•

Relaxation programs and massage

Referral

Consider referral to a subspecialist in this area, such as a dentist or ENT if initial therapy fails to resolve symptoms. Surgery is not recommended.

Pearls & Considerations

Comments

BMS is a rare but possibly debilitating disease that can be highly frustrating to the patient and the practitioner. The patient often experiences an unremitting burning pain in the mouth without any apparent clinical signs, and the practitioner is unable to definitively diagnose symptoms even with the use of laboratory testing or imaging. Other diseases should be ruled out.

Ferri – Burning Mouth Syndrome