Burning Tongue Syndrome

Burning tongue syndrome (burning mouth syndrome) is a chronic burning sensation of the tongue or oral mucosa, lasting at least 3 months, with a normal appearance and no identifiable local or systemic cause. It is a neuropathic pain disorder involving small fibre and central mechanisms.

• It is commonest in postmenopausal women.
• Secondary burning occurs with deficiency, candidiasis, diabetes, xerostomia, drug effects and allergy.
• Anxiety and depression are frequent.

Burning, scalding or tingling of the tongue tip and sides, palate or lips, bilateral, often worse in the evening and better with eating, with dry mouth and altered taste.

• The mucosa looks normal.
• Differential diagnosis: oral candidiasis, iron, B12, folate or zinc deficiency, diabetes, Sjogren syndrome, lichen planus, geographic tongue, contact allergy, ACE inhibitor effect, reflux, trigeminal neuralgia, hypothyroidism, ill fitting dentures.
• Complications: sleep disturbance, depression, anxiety, weight loss, reduced quality of life.

Diagnosis is made by exclusion.

• Full blood count, ferritin, vitamin B12, folate, zinc, glucose or HbA1c, thyroid function test.
• Swab for candida, assessment of salivary flow and denture fit; patch testing if allergy suspected.
• Review of drugs, including ACE inhibitors, and of oral habits such as tongue thrusting.

Treat identified causes, then manage the neuropathic pain.

• Supportive: reassurance that it is benign, avoid hot, spicy and acidic food, alcohol and tobacco, sip cool water, sugar free gum, cognitive behavioural therapy, saliva substitutes for dry mouth.
• Pharmacological: clonazepam 0.5 mg tablet sucked for 3 minutes then spat out, three times daily (or 0.25 mg at night orally, increased to 1 mg); alpha lipoic acid 600 mg daily for 2 months; amitriptyline 10 mg at night increased to 25 to 50 mg; gabapentin 300 mg at night increasing to 900 to 1800 mg daily in divided doses; capsaicin 0.025 percent oral rinse in resistant cases. Correct deficiencies and treat candida with nystatin 100,000 units/mL 4 to 6 mL four times daily.
• Procedures: none routinely.
• Special groups: pregnancy, reassurance and non drug measures; older adults, start low and monitor sedation; depression, treat concurrently.
• Red flags: visible ulcer, white patch, mass, numbness, weight loss, unilateral symptoms, lymph node enlargement.
• Follow-up: review at 4 to 6 weeks; psychological support and specialist referral if symptoms persist.