What are Canker Sores Caused By and What Should One do About Them?

Jamie J. Alexander on June 22, 2021

“From time to time, my Boynton Beach dental patients ask me about small sores in their mouths,” says Jamie J. Alexander, DDS. “Most commonly they are small, shallow ulcers (lesions) in the mucous membranes of the mouth that are known as canker sores. Like cold sores that you may have experienced on the outside of your lips, they can occur repeatedly throughout life and be painful – BUT unlike cold sores which are caused by herpes simplex virus HSV-1 or HSV-2, canker sores are not contagious and should go away within a week or two.”

What are Canker Sores Caused By?

Multiple factors increase the risk of canker sores. Unlike cold sores, there is no one specific virus to blame. They occur more often in teens and young adults, females, and within specific families due to their shared heredity for allergens and certain diseases listed below.
Research studies indicate canker sores are commonly found in association with:

  • Emotional stress
  • Hormonal changes
  • Food allergies
  • Lack of B-12, zinc, folic acid, or iron in the diet
  • Exposure to certain chemicals in foods and drinks
  • Toothpaste and mouth rinses containing sodium lauryl sulfate
  • Helicobacter pylori, the same bacteria that cause peptic ulcers, occurring in the mouth
  • Trauma to the soft tissue from a poking orthodontic wire, a rough tooth, or even minor trauma while tooth brushing
  • Crohn’s disease, celiac disease, and Behcet’s disease
  • Diseases that suppress the immune system
  • A faulty immune system that attacks healthy cells of the mouth

Is There Prevention or Cure for Canker Sores?

There is no cure for canker sores, but you may be able to speed up recovery by using the comfort measures listed at the end of this article. If you have flare-ups when you eat specific foods, for example, strawberries, avoid these foods. If you have been brushing too hard along your gum line and accidentally injuring soft tissue, brush softer. You may be able to reduce how often you get them with a healthier diet. If you have been under stress, give yourself permission to take a break and relax.

What if Canker Sores are Unusually Bad?

If you have an unusual spot inside your mouth that is painful and lasts, it could be a canker sore or a sign of oral cancer. Doctors have also reported unusual mouth ulcers and tongue rashes in some COVID-19 infected patients.
Check with your doctor if you have a mouth ulcer that does not heal within two weeks. If you have recurring sores or fever at the same time as a painful mouth sore, also check with your doctor. If you have a rough tooth or orthodontic wire that is irritating the lining of your mouth or tongue, seek immediate help from your dentist or orthodontist.
Here are some oral hygiene tips and comfort measures while suffering from canker sores:

  1. Brush teeth softly in the area and do not brush at the site of an ulcer.
  2. Rinse your mouth with plain water to rinse away toothpaste.
  3. Rinse with a mild, peroxyl antiseptic, alcohol-free mouth rinse.
  4. Gently swish a warm water salt rinse over the canker sore multiple times a day.
  5. Do not floss with string floss near ulcers. Use a WaterPik on its lowest setting.
  6. Eat soft, bland foods and avoid sugar.
  7. Avoid drinking alcohol and acidic beverages.
  8. Drink lots of water to keep your mouth hydrated.
  9. You can suck on ice chips to numb the painful area but be careful not to irritate it more.