Why Do Babies and Children Get Black Tongues?

If your child has developed a black tongue, it is most likely a harmless medication side effect, typically associated with over-the-counter antacids or prescription antibiotics. The condition resolves on its own, or sometimes requires treatment with gentle, superficial scraping, such as at the dentist's office.

Adults can have more concerning causes of a black tongue, including smoking, cancer, side effects of chemotherapy, or bleeding, but these issues rarely affect children.

Doctor using tongue depressor to look in girl's mouth
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Causes

Pepto Bismol is the most common cause of black tongue in children. Pepto Bismol, as well as other antacids, contains bismuth, a medication ingredient that can cause a black discoloration or staining on your tongue for a few days. It occurs when bismuth combines with the sulfur that's in saliva, forming bismuth sulfide.

When it's caused by medication, black tongue is harmless and goes away a few days after you stop taking the medication.

Other common causes of black tongue in children include:

  • Drinking or eating something with a black dye or food coloring
  • Drinking or eating something with a natural dye, like blackberries
  • Bacteria in the mouth, which can also produce sulfur compounds, potentially leading to a black tongue
  • Lingua villosa nigra (black hairy tongue), which is caused by an overgrowth of bacteria or yeast on the tongue
  • A pigmented nevus (birthmark) on the tongue

Pepto Bismol and Reye's Syndrome

Pepto Bismol can be effective for treating Helicobacter pylori (H. pylori) in children. H. pylori is associated with gastrointestinal (GI) ulcers. But the safety of this medication has not been well established for children.

The main ingredient in Pepto Bismol, bismuth sub-salicylate, has been linked with Reye's syndrome, a potentially life-threatening disorder that can affect kids who take certain medications.

Due to the association with Reye's syndrome, the FDA limits the use of regular formulations of Pepto Bismol and Kaopectate (which also contains bismuth sub-salicylate) to children over age 12.

Symptoms

For children, the physical appearance of the tongue is usually the most bothersome effect of black tongue. Sometimes, children may also have other symptoms along with black tongue.

Common symptoms that can accompany black tongue include:

Since there's also sulfur in the GI tract, taking medications with bismuth can sometimes also temporarily darken the stool.

Treatment

If you notice that your child has developed black tongue due to antibiotics or antacids, the condition will resolve once the medication course is completed. But sometimes the condition has to be treated.

If your child's doctor thinks that their black tongue is caused by an infection, they will prescribe treatment with antifungals or antibiotics to resolve the infection.

Once your child is feeling better, it might be a good time to review their oral hygiene regimen and ensure that they are brushing and flossing well. If they have skipped dentist appointments, now is the time to catch up.

Prevention

Since Pepto Bismol is the most common cause of black tongue, giving your child the children's version (which can be given to children as young as 2 years old) could be the best prevention.

Instead of bismuth sub-salicylate, Children's Pepto Chewable Tablets only contain calcium carbonate as the active ingredient. So, unlike the other forms of Pepto Bismol, it would not be associated with Reye's syndrome or with black tongue.

Sometimes, a nutritional deficiency, such as vitamin C deficiency, can contribute to the risk of black tongue that's caused by an infection. If your child has been avoiding certain foods, talk to their pediatrician about whether they should take vitamin supplements.

When to Call a Doctor

If your child has pain, swelling, bleeding, or discharge from their tongue, gums, or anywhere in their mouth, be sure to get medical attention.

Additionally, if your child has abdominal pain, vomiting, hematemesis (vomiting blood), or a high or persistent fever, talk to their doctor.

Frequently Asked Questions (FAQs)

Can Pepto Bismol turn your tongue black?

Yes, the Pepto Bismol that's made for adults can turn your tongue black. The children's version of Pepto Bismol should not turn your tongue black.

What makes a tongue turn black?

When the sulfur in your body combines with the bismuth in some medications or with bacteria or fungus, the chemical reaction can turn your tongue black.

How do I get rid of my child's black tongue?

If your child's black tongue is caused by medication, you can ask their doctor to recommend or prescribe a different medication. Sometimes a gentle scraping at the dentist's office can remove it. If it is caused by an infection, then the infection should be treated.

How long does black tongue last?

Black tongue should resolve a few days after the cause is taken care of.

A Word From Verywell

If you are a parent, your child's black tongue can look scarier than it really is. And your child might be concerned or embarrassed about the way their tongue looks. Rest assured that it should resolve shortly after they stop taking antibiotics or bismuth-containing medication. Make sure to take your child to the pediatrician if their black tongue isn't caused by medicine with bismuth or if it doesn't quickly go away.

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