Canker Sores
Canker Sore Overview
Canker sores, also known as aphthous stomatitis, are
among the most common causes of painful sores in the mouth.
- From 20%-40% of the U.S. population have them at some
point in their lives.
- The peak incidence occurs among people in adolescence
and young adulthood. They become less frequent as we get older.
- They are not contagious.
- Canker sores are not the same thing as cold sores. Cold
sores ("fever blisters") occur on the outer lip, whereas canker sores are found inside the mouth.
Canker Sore Causes
No one knows what causes canker sores. The vast majority of people who develop canker sores do not have another problem as the cause.
- The disease is suspected to result from a reaction of
the immune system.
- Additional causative factors may include the
following:
- bacterial infections
- hormonal disorders
- stress
- trauma
- heredity
- drugs (including anti-inflammatory drugs, such as ibuprofen, and beta-blockers, such as atenolol)
- food allergies or sensitivities (chocolate,
tomatoes, nuts, and acidic foods such as pineapple)
- toothpastes containing sodium lauryl sulfate
- deficiencies of iron, folic acid, or vitamin B12
- Recurrent canker sores have been associated with
inflammatory bowel diseases, such as Crohn disease and ulcerative colitis. In these
cases, the development of canker sores may signal a flare-up of the bowel
disease.
- Celiac, or abdominal, sprue, a disease of the intestines caused by sensitivity to gluten, causes
malabsorption and is associated with development of canker sores. Gluten
refers to a group of proteins found in wheat, barley, and rye.
- Behçet disease is a condition characterized by canker
sores, genital sores that resemble canker sores, and inflammation of the
eye.
- Infection with the AIDS virus also has
been associated with canker sores.
- It is a common misconception that canker sores are a form of herpes infection. This is not the case.
Canker Sore Symptoms
Canker sores occur in several forms. They can involve
any area of the mouth except for the gums, lips, and hard palate.
- Minor canker sores (which account for the majority of
aphthous ulcers) are oval and less than 10 mm (1/3 inch) across. Most are 2-3
mm with a white center. They are painful but clear up within three to 14 days
without scarring. It is unusual for them to become infected.
- Major canker sores consist of deep ulcers measuring
greater than 1 cm (1/3 inch). These ulcers, which are very painful, have
irregular margins and often last for three to six weeks. They tend to heal
with extensive scarring.
- A third form of canker sores, termed "herpetiform,"
resemble herpes infections and consist of many small shallow punched-out
lesions, pinhead-sized (1-3 mm) in diameter, or less than one-tenth of an
inch. Clusters of these sores may merge together to form large irregular
ulcers. They last from seven to 10 days.
- Canker sores commonly come back. Some people have a few outbreaks a year,
while others can have them almost all the time.
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