Stomatitis (Child)

Stomatitis is pain inside the mouth. It can involve open sores (canker sores) or redness and swelling. It occurs on the inside of the cheeks or on the tongue or gums. Stomatitis is more common in children, but it can occur at any age.


There are many causes of stomatitis, but the most common is viral infections. Other common causes are:

  • Injury or irritation of the mouth lining

  • Fungal or bacterial infections

  • Using tobacco

  • Irritating foods or chemicals, such as citrus fruit, toothpaste, or mouthwash

  • Lack of certain vitamins, including vitamins B and C

  • A weakened immune system


Stomatitis can result in a variety of symptoms, including:

  • Redness inside the mouth

  • Sores (ulcers) in the mouth

  • Pain or burning

  • Swelling

  • Fever


For a viral infection, usually only the symptoms are treated. Antibiotics do not kill viruses and are not recommended for this condition. This infection should go away within 7 to 10 days.

Home care

  • Use a local numbing solution for pain relief. Ask the pharmacist for suggestions on which brand and strength is best for your child. You may apply this directly to the sores with a cotton swab or with your finger. Use the numbing solution just before meals if eating is a problem.

  • Older children may rinse their mouth with warm saltwater (½ teaspoon of salt in 1 glass of warm water). Be certain they spit the rinse out and don’t swallow it.

  • Feed your child a soft diet, along with plenty of fluids to prevent dehydration. If your child doesn't want to eat solid foods, it's OK for a few days, as long as he or she drinks lots of fluids. Cool drinks and frozen treats are soothing. Avoid citrus juices (orange juice, lemonade, etc.) and salty or spicy foods. These may cause more pain in the mouth.

  • Follow the healthcare provider's instructions on the use of over-the-counter pain medicines such as acetaminophen for fever, fussiness, or pain. In infants older than 6 months, you may use children's ibuprofen. (Note: If your child has chronic liver or kidney disease or has ever had a stomach ulcer or gastrointestinal bleeding, talk with your child’s healthcare provider before using these medicines.) Don’t give aspirin to a child younger than age 19 unless directed by your child’s provider. Taking aspirin can put your child at risk for Reye syndrome. This is a rare but very serious disorder. It most often affects the brain and the liver.

  • Children should stay home until their fever is gone and they are eating and drinking well.

Follow-up care

Follow up with your child’s healthcare provider, or as advised.

If a culture was done, you will be notified if the treatment needs to be changed. You can call as directed for the results.

Call 911

Call 911 if any of these occur:

  • Trouble breathing

  • Inability to swallow

  • Extremes drowsiness or trouble waking up

  • Fainting or loss of consciousness

  • Rapid heart rate

  • Seizure

  • Stiff neck

When to seek medical advice

For a usually healthy child, call your child's healthcare provider right away if any of these occur:

  • Your child has a fever (see Fever and children, below).

  • Your child can't eat or drink due to mouth pain.

  • Your child shows unusual fussiness, drowsiness, or confusion.

  • Your child shows symptoms of dehydration, including no wet diapers for 8 hours, no tears when crying, sunken eyes, or a dry mouth.

Always use a digital thermometer to check your child’s temperature. Never use a mercury thermometer.

For infants and toddlers, be sure to use a rectal thermometer correctly. A rectal thermometer may accidentally poke a hole in (perforate) the rectum. It may also pass on germs from the stool. Always follow the product maker’s directions for proper use. If you don’t feel comfortable taking a rectal temperature, use another method. When you talk to your child’s healthcare provider, tell him or her which method you used to take your child’s temperature.

Here are guidelines for fever temperature. Ear temperatures aren’t accurate before 6 months of age. Don’t take an oral temperature until your child is at least 4 years old.

Infant under 3 months old:

  • Ask your child’s healthcare provider how you should take the temperature.

  • Rectal or forehead (temporal artery) temperature of 100.4°F (38°C) or higher, or as directed by the provider

  • Armpit temperature of 99°F (37.2°C) or higher, or as directed by the provider

Child age 3 to 36 months:

  • Rectal, forehead, or ear temperature of 102°F (38.9°C) or higher, or as directed by the provider

  • Armpit (axillary) temperature of 101°F (38.3°C) or higher, or as directed by the provider

Child of any age:

  • Repeated temperature of 104°F (40°C) or higher, or as directed by the provider

  • Fever that lasts more than 24 hours in a child under 2 years old. Or a fever that lasts for 3 days in a child 2 years or older.

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© 2000-2020 The StayWell Company, LLC. 800 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.