Burning mouth syndrome and menopause: a burning tongue with nothing to see

What the experience is like

A burning, scalding or tingling sensation, most often on the tip and sides of the tongue, sometimes the lips, palate or the whole mouth. Frequently accompanied by a dry sensation despite normal saliva flow, and by a persistent metallic or bitter taste.

The characteristic pattern is that it is absent or mild on waking and builds through the day, and that eating and drinking often relieve it rather than aggravate it — which is the opposite of what an ulcer or infection does, and is a useful diagnostic clue.

And the mouth looks entirely normal. That combination of severe symptom with nothing to see is why people are so often disbelieved, and why they can spend years cycling between dentists and doctors.

The menopause connection

The demographic pattern is striking: burning mouth syndrome affects women far more than men, and incidence clusters in the perimenopausal and postmenopausal years.

Proposed mechanisms include estrogen's effect on oral mucosa, which thins as levels fall much as genital tissue does; changes in saliva composition; and effects on the small sensory nerve fibres of the tongue, with some research finding reduced small fibre density in affected people. A taste-pathway component has also been described, in which loss of normal inhibition from taste nerves allows pain signalling to increase.

Evidence that hormone therapy treats it is limited and inconsistent, so it should not be assumed to be the answer.

What must be excluded first

This is a diagnosis of exclusion, and several of the alternatives are common, easily missed and straightforward to treat:

• Iron, ferritin, vitamin B12, folate and zinc deficiency
• Thyroid disease and diabetes
• Oral candidiasis, which can cause burning with minimal visible change
• Dry mouth from medication — antidepressants, antihistamines, blood pressure drugs
• Allergy or reaction to dental materials, toothpaste ingredients such as sodium lauryl sulfate, or denture components
• Acid reflux reaching the mouth
• Parafunctional habits: tongue thrusting, clenching, mouth breathing

What helps once it is diagnosed

Treatment aims at the nerve signalling rather than the mouth. Clonazepam used topically — dissolved in the mouth rather than swallowed — has the best evidence of the drug options. Low-dose medications used for neuropathic pain are also used, and cognitive behavioural therapy has evidence for reducing symptom severity and distress.

Practical measures with reasonable support: avoiding toothpastes containing sodium lauryl sulfate, avoiding acidic and spicy foods during flares, sipping cold water or sucking ice chips, and treating any dry mouth properly.

It is worth knowing that this condition frequently improves or resolves over several years, which is genuinely useful information for someone who has been told nothing is wrong.

When to see someone

Ask for the deficiency screen and thyroid function explicitly, because this is the step most often skipped, and a ferritin result can end the whole problem.

Get any visible change assessed separately rather than folded into this diagnosis — a white or red patch, an ulcer lasting more than three weeks, or a lump needs examining in its own right.