Canker Sores

Definition

Painful, shallow ulcers (sores) on the inner lips or cheeks
Not caused by an infection

Call or Return If

Mouth ulcers last more than 2 weeks
You think your child needs to be seen
Your child becomes worse

About This Topic

Symptoms

Small ulcers have a white center with a red border around them
Size is usually less than ¼ inch (6 mm)
Found on the inner lips and inner cheeks
The sores are very painful, even when not eating
Usually get 1 canker sore at a time. Sometimes get 2 or 3.
No fever or other symptoms

Causes

Canker sores have many causes. Often, the cause is unknown.
Minor injuries to the mouth can trigger a canker sore.
Examples are from a rough food or a hard toothbrush. Biting oneself while chewing can start one.
Food allergies or irritants may also be a trigger.
More common during menstrual periods
Vitamin deficiencies can also be a cause. A vitamin deficiency can occur if your child is a picky eater.
Canker sores can run in families (genetic).
Not caused by the Herpes virus or other infections

After Care Advice

Overview:

Canker sores are the most common cause of unexplained mouth ulcers.
They happen in healthy children.
They are harmless and go away on their own.
Here is some care advice that should help.

Liquid Antacid for Mouth Pain:

For mouth pain, use a liquid antacid such as Mylanta or the store brand. Give 4 times per day as needed. After meals often is a good time. Age: Can use for children over 1 year old.
For children over age 6, can use 1 teaspoon (5 ml) as a mouth wash. Keep it on the ulcers as long as possible. Then can spit it out or swallow it.
For younger children age 1 to 6, put a few drops in the mouth. Can also put it on with a cotton swab.
Can use honey instead until you can buy a liquid antacid. Follow the same directions as given for antacids. Avoid honey if less than 1 year old.
Caution: Do not use regular mouth washes, because they sting.

Pain Medicine:

To help with the pain, give acetaminophen (such as Tylenol) or ibuprofen. Use as needed.

Fluids and Soft Diet:

Try to get your child to drink adequate fluids.
Goal: keep your child well hydrated.
Cold drinks, milk shakes, popsicles, slushes, and sherbet are good choices.
Solids. Offer a soft diet. Also avoid foods that need much chewing. Avoid citrus, salty, or spicy foods. Note: Fluid intake is more important than eating any solids.

Vitamins:

If your child is a picky eater, start your child on a multi-vitamin. Give daily.

Prevention of Recurrent Canker Sores:

Avoid minor injuries to the inside of the mouth.
Avoid any foods that you think are a cause.
Fix any dental problems that are present.

What to Expect:

Canker sores heal up in 1 to 2 weeks on their own.
Once they start, no treatment can shorten the illness.
Treatment can help with the pain.
Some children get recurrent canker sores.

Return to School:

Children with canker sores do not need to miss any school.
Canker sores cannot be spread to others.

Author: Barton Schmitt MD, FAAP
Copyright 2000-2021 Schmitt Pediatric Guidelines LLC
Disclaimer: This health information is for educational purposes only. You the reader assume full responsibility for how you choose to use it.
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