Mouth Ulcers



Return to School

When to Call Us for Mouth Ulcers

Call 911 Now (your child may need an ambulance) If

  • Not moving or too weak to stand
  • You think your child has a life-threatening emergency

Call Us Now (night or day) If

  • Your child looks or acts very sick
  • Chemical in the mouth could have caused ulcers
  • Dehydration suspected. (No urine in over 8 hours, dark urine, very dry mouth and no tears)
  • You think your child needs to be seen urgently

Call Us During Weekday Office Hours If

  • You have other questions or concerns
  • Mouth ulcers last more than 2 weeks

Parent Care at Home If

  • Canker sores suspected


Canker sores are the #1 cause of mouth ulcers:
  • 1 to 3 painful, white ulcers of the inner cheeks, inner lip or gums (no fever).
  • Causes include injuries from rough food, tooth brushes, biting, or food irritants.
  • 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: 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. See Dose Table.
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.
  • For infants, you may need to stop the bottle. Give fluids by cup, spoon or syringe instead. Reason: The nipple can increase the pain.
Return to School:
  • Canker sores cannot be spread to others.
  • Children with fever need to be checked before going back to school.
  • Also, children with many mouth ulcers should be checked before going back.
What to Expect:
  • They 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.
Call Your Doctor If:
  • Mouth ulcers last more than 2 weeks
  • Your child becomes worse
Canker Sore on Inner Lower Lip

Chickenpox Sores in Mouth

And remember, contact us if your child develops any of the "Call Us" symptoms.

Author and Senior Reviewer: Barton D. Schmitt, M.D.

Copyright 1994-2013 Barton D. Schmitt, M.D.