Geographic tongue: causes, symptoms and treatment

The exact cause is not known. BISOM says geographic tongue is not caused by an infection and cannot be passed on to others, and is thought to be a normal variation in how the tongue looks rather than a disease. The NI Direct page likewise says the cause is not clear.

It can sometimes run in families, but BISOM says the genetic link is not clear. A small number of people with geographic tongue may also have psoriasis on their skin.

Geographic tongue is a common, harmless condition affecting the surface of the tongue. It appears as red, smooth patches with irregular white or pale borders, which can look like a map and give the condition its name. It is also called erythema migrans (migrating redness) and benign migratory glossitis (harmless migratory inflammation).

NI Direct says the patches can vary in size and may occur on one area of the tongue before moving to another after a few days, weeks or months. BISOM adds that they can move, disappear and reappear in different areas over time.

Some people also have deep grooves on the tongue, known as a fissured tongue. Occasionally similar patches can appear inside the lips, cheeks or on the palate (roof of the mouth).

Often there are no symptoms. BISOM says some people notice that the tongue feels sore or sensitive, especially after eating spicy, acidic or salty foods. NI Direct says in some people the patches can feel sore or sensitive when consuming certain foods and drinks.

BISOM says a dentist or doctor can usually diagnose it by looking at your tongue and asking a few questions, and that you do not usually need any tests. If the patches are not visible at the appointment, showing photos from when they were present can help.

BISOM adds that if your tongue is particularly uncomfortable, blood tests may be arranged to check for anaemia, vitamin deficiencies and other possible causes of a sore tongue.

BISOM says geographic tongue does not affect your general health and is not linked to mouth cancer. The leaflet from Royal United Hospitals Bath, adapted from the British Society for Oral Medicine, describes it as a benign condition with no association with oral cancer.

Even so, NI Direct advises seeing your dentist or GP if you have persistent, discoloured or painful patches on your tongue, so that other causes of tongue changes can be checked.

BISOM says there is no cure, but it is harmless and often comes and goes on its own. Most people do not need treatment. Treatment is only needed if the tongue feels painful or sore.

The options BISOM lists are benzydamine hydrochloride (for example Difflam) spray or mouthwash, available over the counter or on prescription, which is especially helpful before meals or toothbrushing, and anaesthetic gels, ointments, liquids, sprays or lozenges to numb the tongue before meals. It advises avoiding mouthwashes that contain alcohol and lozenges that contain sugar.

NI Direct says there is no specific treatment, that you may be able to manage pain with over-the-counter painkillers after asking a pharmacist, and that you should avoid anything that makes it worse, such as acidic, spicy or hot foods.

NI Direct lists several other causes of a painful or changed tongue alongside geographic tongue, including oral thrush, which causes white patches in the mouth and is an infection caused by a fungus. Because the cause of a tongue change is not always obvious by eye, it is worth having new, persistent or painful patches looked at.

BISOM says geographic tongue is less common in children but can affect people of all ages. NI Direct says some people with geographic tongue find it improves over time, while for others it may be more persistent. If a child has a sore tongue or patches that do not settle, a dentist or GP can check.

Most people are reassured by a dentist or GP and do not need a referral. An oral medicine specialist may see people whose symptoms are persistent or troublesome. Private dentists and oral medicine clinics make the same diagnosis from examination; tests are not usually needed.