What does this mean?
A healthy tongue surface is matt and slightly rough thanks to its fine papillae. When these papillae are lost the surface flattens; with the network of blood vessels underneath left uncovered, the colour turns bright red and the tongue looks polished in the light. The tissue also becomes thinner, so sensitivity to hot, spicy and acidic food increases and a burning feeling can appear.
What separates this picture from geographic tongue is how widespread and how lasting it is. In geographic tongue the red areas come as islands, have a whitish border around them and change position within days. Here the whole surface, or a large part of it, flattens at the same time, there is no clear border, and the appearance stays the same for weeks. The second distinguishing point is what comes with it: cracks at the corners of the mouth, pale skin, tiring easily, breathlessness and brittle nails may be reported over the same period.
The causes most often talked about for loss of papillae are deficiencies of iron, vitamin B12 and folate; these deficiencies show early in fast-renewing tissues, and the mouth is often the first place they call. Anaemia, absorption problems, a restricted diet, long-term use of stomach medicines and some situations after surgery can set the scene. A dry mouth and oral thrush can produce a similar redness, so telling them apart is done with an examination and a blood test.
A tongue that flattens and turns shiny suggests that renewal of the surface has been disturbed, and the reason is usually outside the mouth. The headings below bring together the conditions that most often accompany this finding.
Likely causes
What helps at home?
- Cut back on hot, spicy and acidic food until the burning settles; a thinned surface reacts to them noticeably.
- Leave aside alcohol-containing mouthwashes and mouth products heavy with mint for a while; they can increase the burning.
- Do not start high-dose iron or vitamin B12 supplements on your own decision; if there is a deficiency, the test results decide the dose and how long you take it.
- When you go to be seen, take with you a list of the medicines you use and the changes in your diet over recent months.
- If pallor, palpitations, breathlessness or unusual tiredness go with the redness.
- If cracks have formed at both corners of your mouth.
- If the burning carries on all day regardless of eating.
- If there is numbness or tingling in the hands and feet, or trouble with balance.
- If there is an ulcer on the tongue that will not heal, or a hardened area gathered at one spot.
Frequently asked questions
- Which tests are asked for with this appearance?
- The decision belongs to the doctor. The tests asked for most often in this picture are a full blood count and ferritin, vitamin B12 and folate levels; depending on the results, further investigations into absorption may come up. The look of the tongue does not make the diagnosis on its own, it points the way.
- Do the papillae come back?
- Once the underlying deficiency is put right, the surface renewing itself and the slightly rough look returning is what is usually expected; that process can take weeks. It is often reported that the burning eases before the appearance does.
- What can a dentist do about this?
- A dentist assesses the findings inside your mouth and rules out causes there, such as oral thrush, irritation from a denture and a dry mouth. Where they think it necessary, they refer you to the appropriate doctor for a blood test. It is a common situation for this finding to be noticed in the mouth and to point to a deficiency elsewhere in the body.
This content is for general information and does not replace an in-person examination. Symptoms overlap between conditions, and a diagnosis can only be made clinically.