Canker Sores

What is a canker sore?

Canker sores are common sores that appear on your child’s tongue or mouth lining. The sores can make eating and drinking difficult for your child.

Canker sores are different than cold sores or fever blisters. Canker sores may not be caused by a virus and do not appear to spread from one person to another.

Canker sores are also called aphthous ulcers.

Signs and symptoms of canker sores

Signs and symptoms may include:

  • painful, red spots up to 1 inch across
  • the area may tingle a few days before the sore appears
  • the sore will develop into whitish-grey sore with a white or yellow coating
  • sores may appear alone or in bundles

Toddlers and young children may refuse to eat because of the sore’s pain and irritation. Some children and adolescents may have fever, swollen lymph nodes and a tired or ill feeling.

Causes of canker sores

Doctors are not certain of the causes of canker sores. There may be many factors, including:

  • diet
  • trauma
  • stress
  • nutritional deficiencies (such as folic acid, vitamin B12, and iron)
  • infection
  • menstruation
  • allergies
  • drug reaction

Sometimes, canker sores appear more often in children with weak or over active immune systems but usually appear in children with normal immune systems.

Most children with cankers have no identifiable cause for their cankers as these usually appear in healthy children.

How your doctor can help your child with canker sores

Most children suffering from canker sores can be treated at home. However, in some cases your child should see a doctor.

Seek medical assistance right away if:

  • Your child is continually getting canker sores. The doctor or other health provider can look into whether your child is getting a balanced diet or if he is missing a certain vitamin. Your child’s doctor may also examine your child for an underlying medical condition.
  • The sores are not settling down or disappearing after 10 days.
  • Some doctors may recommend an anti-inflammatory topical steroid cream or gel to help the healing.

How you can help your child with canker sores

There are ways you can help your child reduce the pain of canker sores. Some of these tips can also help prevent canker sores from coming back. To reduce the pain of canker sores:

  • Avoid feeding your child acidic, spicy or abrasive (scratchy or hard) foods, such as potato chips, salted nuts, lemons or tomatoes, which can aggravate tender mouth sores.
  • Use toothpastes and mouthwashes that do not contain SLS (sodium lauryl sulfate).
  • Do not brush too hard.
  • Use only soft-bristle toothbrushes.
  • Avoid soft drinks.

Key points

  • Canker sores are different than cold sores or fever blisters.
  • Canker sores do not appear to spread from person to person.
  • Signs of canker sores include painful, red spots across the tongue or on the mouth lining.
  • You can help your child by not feeding soft drinks or spicy, acidic or salty foods.

Mark Feldman, MD, FRCPC