Canker sores often run in families. They also are linked with other diseases, including Behcet's syndrome. You may have only one canker sore at a time, or many of them all at once. Most people get one, two or three sores at a time. But some people have 10 or more at a time. Most people get canker sores a few times each year.
Scientists don't know what causes canker sores. Most believe that there is a problem with the body's immune system.
Other conditions cause similar sores:
- Blood and immune system diseases, including HIV
- Vitamin and mineral deficiencies
- Allergies
- Trauma
- Crohn's disease
- Lupus
Canker sores are often confused with cold sores. Cold sores are caused by a virus. No one is sure what causes canker sores.
About 20 of every 100 people get canker sores. Smaller canker sores usually heal within a couple of weeks. They do not leave scars. For most people, they are just annoying. But some people get larger canker sores (almost one-half inch across or larger). These take longer to heal. They can be painful, and may leave scars. These sores sometimes make it hard to eat or speak.
Sometimes a biopsy is needed to make sure the mouth sore is not a different disease. In a biopsy, a small piece of tissue is removed and examined in a laboratory.
To reduce discomfort, you can:
- Eat bland foods
- Rinse with warm water
- Use pain-relieving gels or creams on the sores
People with larger or very painful sores may need steroid medicines. These are gels or creams that are placed on the sores. They make the sores heal faster. They also keep the sores from growing.
Other possible treatments include injected steroids. There are also a few medicines you can take by mouth, but this is for the most serious cases.
