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Mouth Ulcers (Canker Sores)

Description / Symptoms

Painful, shallow ulcers (sores) on the lining of the mouth.The gums, the inner sides of the lips or cheeks are the usual sites. Sores on the outer lips (e.g. recurrent fever blisters) are excluded.

Cause

  • 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, mainly on the tongue and sides of the mouth. It is common between ages 1 to 5 years
  • First infection with herpes virus (cold sores virus): 10 or more mouth ulcers on the gums, tongue and lips; usually ages 1 to 3 years

See More Appropriate Topic (instead of this one)

If have thick-walled, small-blisters on the palms or soles, in addition to mouth ulcers, see hand-foot and mouth disease.

When to Call Your Doctor for Mouth Ulcers (Canker Sores)

Call 911 Now If:

  • Not moving or too weak to stand

Call Your Doctor Now If:

  • Your child looks or acts very sick
  • Chemical in the mouth could have caused ulcers
  • Signs of dehydration (very dry mouth, no tears and no urine in > 8 hours)

Call Your Doctor Within 24 Hours If:

  • You think your child needs to be seen
  • 4 or more ulcers
  • Bloody crusts on lips
  • Red, swollen gums
  • One ulcer on the gum near a tooth with a toothache
  • Fever or swollen face
  • Large lymph node under the jaw
  • Began after starting a medicine

Call Your Doctor During Weekday Hours If:

  • You have other questions or concerns

Home Care (Read "Call Your Doctor…" first):

Canker sores

The #1 cause of mouth ulcers:

  • 1 to 3 painful, white ulcers of the inner cheeks or gums (no fever)
  • Causes include injuries from rough food, tooth brushes, biting, food irritants, etc

Antacid

Use an antacid solution 4 times per day for pain relief. Children over age 4 can use 1 teaspoon as a mouth wash after meals (Some parents prefer regular mouth washes, but they may sting).

For younger children, put ½ teaspoon in the front of the mouth after meals.

Pain Medicine

Give acetaminophen (e.g. Tylenol) or ibuprofen for severe pain (especially at bedtime).

Fluids

Offer a soft diet. Encourage favorite fluids to prevent dehydration. Cold drinks, milkshakes, and Popsicles are especially good. Avoid salty foods, citrus fruits and foods that need much chewing.

For infants, give fluids by cup, spoon or syringe rather than a bottle. (Reason: the nipple can cause pain).

Contagiousness

Canker sores are not contagious. Children with fever or many mouth ulcers need to be examined before returning to day care or school.

Expected Course

They heal up in 1 to 2 weeks. Once they occur, no treatment can shorten the course, but treatment can reduce the amount of pain.

Call Your Doctor If:

  • Mouth ulcers last > 2 weeks
  • Your child becomes worse or develops any of the "Call Your Doctor…" symptoms

Parent Care for Pediatric Symptoms. Copyright 2000-2009.