Canker Sores

Also known as "aphthous ulcers" or "aphthous stomatitis", canker sores are a common form of mouth ulcer characterised by shallow, painful sores that occur on the lining of the mouth. Around 10% of the population will develop canker sores at some point in their life. Anybody can develop canker sores, but they are slightly more common in teenagers young women.

Canker sores are not contagious, so you can not catch them or pass them on to others. The exact cause of them is not known but it is believed that some people have a genetic predisposition to developing canker sores.

Aggravating factors may include;

• Orthodontic braces.

• Spicy, hot, acidic foods (citrus).

• Stress.

• Lack of sleep.

• Physical trauma - Dentures, braces etc.

• Bacterial infections.

• Celiac disease.

• HIV/AIDS.

• Drugs.

• Toothpastes containing sodium lauryl sulfate (SLS).

• Certain vitamin & mineral deficiencies (vitamin B12, folic acid, iron).

• Hormonal changes. Women can develop canker sores just prior to menstruation.

Canker sores symptoms:

The first symptom of a canker sore is a tingling or burning sensation which forms a red spot, followed by a painful, oval or round white/yellow ulcer which has an inflamed, red border. The sore may turn a greyish colour as it begins to heal.

In some cases, fever may be present along with painful lymph nodes in the area. 

There are three types of canker sores which are classified according to the size of the sore.

Minor ulceration

• Painful, white/yellow sore between 1mm and 10mm in diameter. Most canker sores fall into this category.

Major ulceration

• Painful, white/yellow sore greater than 10mm in diameter.

Herpetiform ulcerations

• Multiple, small, white/yellow sores between 1mm & 3mm in diameter.

Canker sores treatment:

Most sores will resolve on their own within one to two weeks. Large ulcers will take longer to heal.

Avoiding spicy and acidic foods & switching toothpaste to one which doesn't contain SLS is advisable. Mild, over the counter mild washes or warm, salt water solutions to swish around the mouth can help to speed up healing. Over the counter painkillers such as Ibuprofen can also relieve discomfort.

If canker sores are large or haven't healed within two weeks, seek medical advice.

Treatment for major ulcerations may include;

• Topical ointments which are applied to the sores to relieve pain & speed healing.

• Mouth rinses which contain steroids, and or local anesthetics to help with pain and inflammation. 

• Anti-inflammatory gels to reduce inflammation.

• Oral medications such as corticosteroids may be prescribed for severe cases. Other oral medications originally used to treat other medical conditions may also be of use to treat canker sores.

• Vitamin supplements if you are found to be deficient.

Also see:

Cold sores

Please note:

The medical articles on this site have not been written by a doctor & should not be considered a replacement for a doctor visit. The articles are provided for informative purposes only.

Always seek immediate medical advice for any problems.

While great care has been made in the creation of these articles, we cannot guarantee the accuracy or omissions on these pages. If in any doubt whatsoever, seek professional medical advice.