The Causes of a Red Tongue

If you open your mouth and discover you have a red tongue, should you be concerned? Here’s what causes a red or strawberry colored tongue.

Like fingernails, a person’s tongue says a lot about their general health – which is why doctors typically ask patients to stick out their tongue during a physical exam. A healthy tongue is usually moist and pink in color with a thin, white surface coating. On the other hand, the relatively smooth, pink appearance of the tongue can be altered by various diseases – or by malnutrition, vitamin deficiencies, smoking, or poor oral hygiene. What if you open your mouth and discover you have a red tongue instead of the normal pink color? Should you be concerned?

Strep Infection Can Cause a Red Tongue

One of the more common causes of a red tongue or “strawberry tongue” is an infection with a strep bacteria – leading to scarlet fever. A person with scarlet fever typically has a sore throat and fever with a red rash and a flaming, strawberry red tongue that’s quite distinctive in appearance. A doctor can usually make this diagnosis by physical exam and a positive throat culture for strep. Fortunately, the strawberry tongue goes away after treating the strep infection with antibiotics.

Another Cause of a Red Tongue in Children

A less common cause of a red tongue in children is Kawasaki’s disease, an uncommon disease that affects mostly children under the age of five. It’s believed to be an autoimmune condition – possibly triggered by a virus – and involves inflammation of blood vessels throughout the body. This includes the coronary vessels of the heart which can lead to aneurysm formation.

A child with this disease typically has a high fever, swelling of the lymph nodes, red eyes, cracked lips, red mucous membranes – and a red tongue. The tongue has a characteristic “strawberry tongue” appearance and the back of the tongue has prominent “bumps” due to enlargement of the papillae. This disease can be difficult to distinguish from scarlet fever. Any child with a strawberry tongue and fever needs an immediate evaluation by a doctor due to the serious nature of this disease.

Sore, Red Tongue?: It Could Be a Vitamin Deficiency

A deficiency in vitamin B12 is a common cause of a sore, red tongue. Some people with vitamin B12 deficiency have pernicious anemia, a condition where red blood cells appear very large and immature. People with pernicious anemia don’t absorb enough vitamin B12 because they lack intrinsic factor which is important for its absorption by the intestines.

Not everyone with a deficiency of B12 has pernicious anemia, so it’s important to check a vitamin B12 level and a confirmatory test called an MMA and homocysteine levels in cases of suspected vitamin B12 deficiency. A deficiency in folate, another B vitamin, can also cause a red tongue. Anyone with a sore, red tongue needs a complete blood count and testing for a B12 and folate deficiency.

Other Causes of a Red Tongue

 A deficiency of niacin, another B vitamin, can cause also cause a red tongue. A niacin deficiency leads to a condition known as pellagra which causes a sore mouth, strawberry tongue, changes in mental status, and diarrhea. Blood tests are used to diagnose this vitamin deficiency.

Don’t forget about more obvious causes of a red tongue. It could be something you ate. If you’ve just eaten a bowl of strawberries or chewed gum with red food coloring, that can do it also. Some acidic foods can cause temporary tongue pain and redness.

The Bottom Line?

A red tongue that’s persistent or associated with other symptoms such as fever or mouth pain should be evaluated by a doctor. Otherwise, look for move obvious causes – such as something you’ve eaten.


Merck Manual. 18th Edition. website. “Common Tongue Conditions in Primary Care Reviewed”

Liked it
RSSComments: 7  |  Post a Comment  |  Trackback URL
  1. Informative article.

  2. Great information :)

  3. Very informative. Thanks for posting.

  4. I read your articles are well received little new information. Your best hope of further articles.

  5. thanks for the important information, I wonder if medication could also cause a red sore tongue.

  6. Great, Thank you very much.

  7. Proper nutrition is important. If we are not getting enough vitamin B, we have to take supplements. It is important to notice if other symptoms accompany the redness. For example, a tingling tongue is one of the signs of multiple sclerosis:

RSSPost a Comment
comments powered by Disqus