Introduction

If you are concerned about any of the following, consult your doctor:

• A bacterial infection develops (symptoms may include severe pain, fever, and swollen lymph nodes).
• Lesions worsen or persist beyond several weeks.
• A more serious problem may be present, such as inflammatory bowel disease or oral cancer. Risk factors for oral cancer include smoking, tobacco chewing, and alcohol use.

Exams and Tests

Canker sores are diagnosed by their typical appearance. In most cases, no testing is needed. However, the doctor must consider the possibility of herpes, fungal infections, trauma, or persistent sores that could signal cancer. Oral lesions of hand-foot-and-mouth disease can resemble canker sores. Canker sores may also be seen in people with HIV, inflammatory bowel diseases, and certain medical conditions. Herpetiform aphthous ulcers lack vesicles (small blisters) before the ulcers appear, distinguishing them from true herpes sores.

Self-Care at Home

Try rinsing your mouth with a solution of ½ teaspoon salt dissolved in 8 ounces of water. Another helpful mixture consists of 1-2 tablespoons of Maalox mixed with ½ tablespoon of liquid diphenhydramine (Benadryl). Swish a teaspoonful in your mouth and spit it out; this can be done four times a day. Over-the-counter medications like calamine (Calamox) lotion can provide relief. Liquids or ointments with a numbing ingredient such as benzocaine (Anbesol, Oragel, Orabase, Zilactin-B, Tanac) can help alleviate canker sore discomfort.

Prevention

• Avoid anything that could cause mouth trauma, even minor trauma, such as hard toothbrushes and rough foods.
• Avoid toothpaste containing sodium lauryl sulfate if you tend to get canker sores.
• Avoid talking while chewing.
• Repair any irregular dental surfaces.
• Hormonal factors can sometimes trigger an outbreak during the premenstrual phase; oral contraceptives may help.
• If you have a deficiency of iron, folic acid, or vitamin B12, ensure you are taking the appropriate supplements.

Unexplained Anemia

Anemia is a condition characterized by fewer red blood cells than expected. Anemia should be investigated. There are various types of anemia, but almost all cases of anemia caused by blood loss lead to iron deficiency anemia. Unless there is an obvious source of ongoing blood loss, this anemia requires evaluation. Many cancers, especially bowel cancer, can cause iron deficiency anemia. Evaluation should include endoscopy or x-ray studies of your upper and lower intestinal tracts.

Outlook

Most people experience minimal inconvenience from canker sores, as attacks are usually infrequent and last only a few days. The more severe form, however, tends to last longer. As you age, canker sores may become less frequent.