Canker sores are small mouth ulcers that may cause severe pain and discomfort. They are usually benign and do not lead to or become oral cancers. These sores usually resolve by themselves. Treatment is usually not necessary.

Two types of treatment of canker sores

Treatment of canker sores may be:

• Symptomatic treatment

This involves local therapy to relieve pain, reduce inflammation and control or treat infections with bacteria or fungi and candida.

• Systemic treatment

This involves therapy that is given orally to address the underlying cause of the sores. If the ulcer cause is unknown and the sore lasts more than three weeks' duration, a specialist review and diagnosis is important.

Caring for canker sores

Caring for the sores include the following steps: avoidance of spicy food, mouth washes, oral gels and paints and so forth. (1-8)

Avoidance of hot or spicy foods

As the sores are extremely painful during the initial 3 to 4 days hot or spicy foods should be avoided as they cause pain.

Foods the person is allergic to, smoking, alcohol, aerated or citrus fruit drinks should be avoided as well.

Mouth washes

These are mild and are available over-the-counter. As an alternative – rinsing with salt water also helps. Salt water rinses contains half a teaspoon of salt in a glassful of warm water or dilute compound sodium chloride mouthwash with an equal amount of water.

The most commonly available mouthwash contains Chlorhexidine. This may be used in patients who are at high risk of canker sores in an attempt to prevent further attacks. This is applicable for patients with a low immunity.

It is available as a mouthwash, gel and spray. Side effects include staining of the teeth brown.

Povidone iodine is another mouth wash that may be used for less than 14 days in severe cases. Longer use is discouraged as it leads to iodine absorption.

Oral gels and paints

These are also over-the-counter medicines that soothe the painful area. They can be applied directly over the sores. These medications contain an antibiotic and a surface anesthetic that numbs the area reducing the pain.

A mixture of half hydrogen peroxide and half water may be prepared and used at home. A cotton swab is used to apply the mixture directly to the canker sore. This is followed by a dab of Milk of Magnesia. The whole process is repeated three to four times a day.

This is soothing and may also help the sore heal. Alternatively half Milk of Magnesia and half Benadryl liquid allergy medicine may be used to swish the insides of the mouth for a minute before spitting it out.

Ulcer-protectives

Carmellose gelatin paste is an ulcer-protective. The gel adheres to the ulcer base and protects it. This hastens healing, reduces risk of injury and pain.

Local anesthetic gels

Local anesthetic gels may be used. These contain Lidocaine as 5% ointment/lozenges or 10% solution spray.

Another local anethetic is Benzydamine hydrochloride that is used as mouthwash or spray. It is licensed for use in children with aphthous ulcers.

Pain killers

Pain killers like Flurbiprofen (available as lozenges) and salicylates (available as oral gel or paste) may be used. These are restricted in children due to risk of salicylate poisoning.

These need to be used cautiously as stagnation of these drugs may lead to ulcers themselves.

Antibiotics

Antibiotics like Doxycycline mouthwash may be helpful in the management of recurrent canker sores. Low-dose oral doxycycline may also be taken as pills.

Prolonged therapy with antibiotics for canker sores may cause oral thrush or mouth candidial infections as complications. If the canker sores are severe and left untreated the bacterial infections may lead to deeper infections like cellulitis or Ludwig’s angina.

Treatment for more severe cases

For severe cases prescriptions of fluocinonide gel (Lidex) or chlorhexidine gluconate mouthwash may be made.

These patients may also require corticosteroids to reduce the inflammation. These may be taken as pills or may be sprayed or applied as gels over the ulcers.

Common corticosteroids used include hydrocortisone hemisuccinate (as pellets or as logenzes), Triamcinolone (available as pastes) and beclomethasone (available as mouth wash and inhaler sprays) etc.

General care for canker sores

Care includes intake of plenty of clear non-acidic fluids. Fluids like cold milk, liquid gelatin, custard, ice cream and yogurt are soothing.

Prevention of canker sores

Prevention of cancer sores involves: –

• Maintenance of dental hygiene. Regular brushing and flossing with routine dental check-ups are important in early detection of causative pathologies like sharp edges of teeth or ill-fitting dentures leading to injury to the lining of the mouth.
• Stress should be avoided and a healthy balanced diet with adequate vitamins, minerals etc., is recommended. Sharp foods like chips, tortillas etc. should be avoided if there are existing sores. Very spicy and citrus foods should be avoided.
• Tooth brushes should be chosen carefully as they may cause damage to gums on vigorous brushing leading to increased propensity for canker sores.
• In some patients multi-vitamins with minerals and antioxidants and the amino acid L-lysine (500mg tablets, 2-4 times daily) is prescribed for prevention of canker sores.

Further Reading

• All Canker Sores Content
• Canker sores – What are canker sores?
• Causes of canker sores
• Symptoms of canker sores
• Diagnosis of canker sores

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.