Springdale Mason Pediatrics

Mouth Ulcers (Mouth Sores) - Symptom


  • Painful, shallow ulcers (sores) on the lining of the mouth
  • Found on the gums, inner lips, inner cheeks, or tongue

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


  • Canker Sores. The main cause of 1 or 2 mouth ulcers after age 5.
  • Hand-Foot-Mouth Disease. The most common cause of multiple ulcers in the mouth. These ulcers are mainly on the tongue and sides of the mouth. Most children also have small deep blisters on the palms and soles. Due to the Coxsackie virus. It is common between ages 1 to 5 years.
  • Herpes Simplex Virus type 1. The first infection can be severe. It can cause 10 or more ulcers on the gums, tongue and lips. Key findings are additional ulcers on the outer lips or skin around the mouth. Also, fever and difficulty swallowing. Usually occurs age 1 to 3.
  • Cold Sores (Fever Blisters). Sores are only found outside the mouth on the outer lip. This recur 2 or 3 times a year in the same place. Since there are no ulcers inside the mouth, they should not be included here.

After Care Advice

  • Canker sores are the most common cause of unexplained mouth ulcers:
  • 1 to 3 painful, white ulcers of the inner cheeks, inner lip or gums (no fever).
  • Causes include injuries from rough food, hard tooth brushes, biting, or food irritants.
  • 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: 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.
  • 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.
  • Solid Foods. Offer soft, bland foods like macaroni and cheese. Other good ones are mashed potatoes, cereals with milk and ice cream.
  • Avoid foods that need much chewing. Avoid citrus, salty, or spicy foods.
  • Note: Fluid intake is more important than eating any solids.
What to Expect:
  • Canker sores heal up in 1 to 2 weeks on their own.
  • Once they occur, no treatment can shorten the illness.
  • Treatment can help with the pain.
Return to School:
  • Children with canker sores do not need to miss any school.
  • Canker sores cannot be spread to others.
  • Children with fever don't have canker sores. Any child with fever can return to school after the fever is gone.

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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