About Canker Sores

Canker sores, also known as aphthous ulcers, are small painful sores inside the mouth. They are most commonly found on the lining of the lips and cheeks but may also occur on the gums and tongue. They may have multiple causes, but infection does not appear to be involved. Canker sores are extremely common; one in five people are affected at any given time.

Identification

• Canker sores appear as shallow white or yellow depressions surrounded by a red edge. Unlike cold sores, they do not appear on the lips and are not contagious. Some people notice a tingling sensation for a day or two before a new sore becomes visible.

Risk Factors

• Why canker sores occur in some people, but not in others, is not well understood, but there are some recognized risk factors for developing the sores. These include a family history of frequent canker sores, smoking, wearing dentures, auto-immune diseases such as lupus, a history of food allergies, and nutritional deficiencies. Some studies have found that toothpaste containing sodium lauryl sulfate might contribute to canker sores.

Type

• Physicians and dentists recognize three types of canker sores--minor, major, and herpetiform. Minor canker sores are by far the most common and consist of a tiny, painful oval sore that heals without scarring in a few weeks or less. Major canker sores have the same general appearance but are much larger, have an irregular border and often leave considerable scarring when they heal. They sometimes last for months or years. Herpetiform canker sores are so named because they resemble cold sores, which are caused by the herpes simplex virus. However, herpetiform canker sores are not contagious and their cause is unknown.

Time Frame

• Canker sores may occur in people of all ages, but they are most common in people between 10 and 30 years old. The first outbreak usually occurs during adolescence, and outbreaks become less frequent with aging. The frequency with which canker sores occurs varies greatly, from once or twice a year to near-continuous outbreaks.

Significance

• Typical canker sores are a nuisance; they do not indicate an underlying health condition. However, frequent, severe outbreaks of canker sores may be the first sign of an auto-immune disorder such as Crohn's disease or lupus. Recurrent canker sores may also be caused by HIV infection, vitamin deficiencies or allergies.