One in five people regularly get bothersome canker sores, which can make eating, drinking and even brushing your teeth a real pain. However, just because they are a relatively common occurrence does not mean canker sores should be ignored.

• What are Canker Sores?
• Signs and Symptoms
• Home Remedies
• Other Helpful Tips

What are Canker Sores?

Also known as aphthous ulcers or aphthous stomatitis, canker sores are small sores that can occur inside a person's mouth, cheeks, lips, throat or sometimes on the tongue. However, canker sores should not be confused with cold sores or fever blisters, which are caused by the herpes simplex virus, and are found outside the mouth around the lips, on the cheeks or chin, or inside the nostrils. Whereas cold sores are contagious, canker sores are not contagious and cannot be spread by kissing.

Although canker sores are not contagious, the tendency to have outbreaks of canker sores can run in a family. If you are prone to canker sores, your children have a 90 percent chance of getting them as well.

Although no one knows exactly what causes canker sores, many factors are thought to put a person at risk including diet, food allergies, mouth injuries and stress. People who have nutritional deficiencies of folic acid, vitamin B12, and iron seem to develop canker sores more often, as do people who have food allergies. Canker sores may also indicate that a person has an immune system problem. Mouth injuries, such as biting the inside of your lip or even brushing too hard and damaging the delicate lining inside your mouth, also seem to bring on canker sores. Emotional stress may even be a factor. For example, one study of college students showed that they experienced more canker sores during stressful periods, such as before an exam, than during less stressful times, like summer break.

Although anyone can get canker sores, young people in their teens and early twenties seem to get the sores most often, and women are twice as likely to develop them as men. Some women find that they get canker sores at the start of their menstrual periods.


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Signs and Symptoms

Canker sores usually appear as painful, red spots that can be up to 1 inch (2.5 centimeters) in diameter, although most of them are much smaller. Sometimes the area will tingle or burn before a spot actually appears. Once it does, the canker sore may swell and burst in about a day. The open sore may then have a white or yellowish coating over it as well as a red "halo." Most often, canker sores pop up alone, but they can also occur in small clusters.

Although uncommon, people with canker sores can also have symptoms such as fever, swollen lymph nodes and a lethargic, or slightly ill feeling.

It takes about two weeks for canker sores to heal. During this time, the sores can be painful, although the first three to four days are usually the worst.


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Home Remedies

Often, canker sores can be easily treated with over-the-counter products or home remedies, which focus on relieving the discomfort associated with the sores. Although these home remedies have not been scientifically studied, there is no harm associated with them when used as directed in this handout. If you have a cold sore that does not heal, see your physician.

Carbamide peroxide is a combination of peroxide and glycerin that cleans out the sore while coating it to protect the wound. Many over-the-counter remedies have benzocaine, menthol and eucalyptol in them. These may sting at first and need to be applied repeatedly; however, they can reduce pain and shorten the duration of the sore.

You can also rinse your mouth with a homemade solution for about one minute, four times a day, as needed. Below are two recipes for rinses. However, it is extremely important to remember not to swallow the rinse.

• Mix 2 ounces (4 tablespoons) of hydrogen peroxide with 2 ounces (4 tablespoons) of water.
  
• Mix 4 ounces (8 tablespoons) of water, 1 teaspoon of salt and 1 teaspoon of baking soda.

Another option to help reduce discomfort and speed healing is dabbing a mixture of equal parts water and hydrogen peroxide directly on the sore, followed by a bit of milk of magnesia.

Some doctors suggest applying a wet black tea bag to the sore. Black tea contains tannin, an astringent that can help relieve pain. You can also get tannin in over-the-counter medications. Ask the pharmacist for more information.

If your doctor prescribes a medicine that should be applied directly to the canker sore, first dry the area with a tissue. Use a cotton swab to apply a small amount of the medication. Finally, avoid eating or drinking for at least 30 minutes to make sure that the medicine is not immediately washed away and has time to treat the sore. In the case of severe mouth sores, your doctor may prescribe treatments such as immunosuppressive drugs, mouth rinses or gels that contain steroids.


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Other Helpful Tips

• Avoid eating abrasive foods that irritate gums and other delicate mouth tissue.
  
• Use only soft bristle toothbrushes and be careful not to brush so hard that they damage the mouth.
  
• Avoid any foods to which you are allergic.
  
• When you have a canker sore, avoid spicy, salty and acidic foods, such as lemons and tomatoes, which can aggravate tender mouth sores

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