TMI - The Monday Inquiry

What are canker sores and how do I prevent and treat them?

Canker Sores

Canker sores, also called recurrent aphthous ulcers, are small round sores that form inside the mouth. They most often appear on the loose tissues of the mouth, like the inside of the lips or cheeks, the underside of the tongue, the floor of the mouth, and sometimes near tonsils. They usually begin as a tingling sensation, followed by a white or yellow sore surrounded by a bright red area. Pain usually decreases in about a week, and the sores heal in 7 to 14 days. Fortunately, most canker sores are not serious and will soon go away on their own.

The causes of canker sores

No one knows what causes canker sores, but some experts say that the tendency to get canker sores is inherited. Another theory is that they may be a result of actions by the body’s immune system. Certain triggers seem to set off outbreaks, including injury in the mouth, like a bite or cut, toothpastes that contain sodium lauryl sulfate, emotional stress, hormonal changes, food allergies, and dietary difficiencies, especially of vitamin B, zinc, folic acid, iron and selenium. If you have had a canker sore, you are likely to get one again. Fortunately, canker sores are not contagious.

Diagnosis and treatment

There is no cure for canker sores, but you can ease the pain and perhaps reduce how often you get them. Common remedies include:

• Using toothpastes and mouthwashes that do not contain lauryl sulfate
• Applying over-the-counter remedies that contain numbing agents, like benzocaine or phenol
• Rinsing with salt water or an antimicrobial mouthwash
• Avoiding spicy or acidic foods during an outbreak
• Working with healthcare provider to treat any food allergies
• Taking a daily multivitamin

If this is the first time you have had a canker sore, let us know, so we can distinguish it from other kinds of mouth sores. Tell us now if you get canker sores more than three times a year, since this may be a sign of a more serious illness. If the sores are large, painful or persistent, we may recommend medication.