What is the treatment for a canker sore?

Treatment for Canker Sores

For canker sores (aphthous ulcers), start with topical mucoprotectant gel (Gelclair) three times daily combined with topical corticosteroid rinses (betamethasone sodium phosphate 0.5 mg in 10 mL water, four times daily), and add benzydamine hydrochloride oral rinse every 3 hours for pain control, particularly before eating. 1

First-Line Treatment Approach

Mucoprotectant Therapy

• Apply Gelclair mucoprotectant gel three times daily to form a protective coating over the ulcerated surface, which reduces pain and promotes healing 1
• If lips are affected, apply white soft paraffin ointment every 2 hours 1

Topical Corticosteroids

• Use betamethasone sodium phosphate 0.5 mg dissolved in 10 mL water as a 3-minute rinse-and-spit preparation four times daily 1
• For localized ulcers, clobetasol propionate 0.05% mixed in equal amounts with Orabase can be applied directly to affected areas daily 1

Pain Management

• Benzydamine hydrochloride oral rinse or spray should be used every 3 hours, particularly before eating 1
• For more severe pain, viscous lidocaine 2% can be applied up to 3-4 times daily 1
• Topical benzocaine products are FDA-approved for temporary pain relief from canker sores 2

Oral Hygiene and Supportive Care

Daily Maintenance

• Clean the mouth daily with warm saline mouthwashes to reduce bacterial colonization 1
• Use antiseptic oral rinses twice daily, such as 1.5% hydrogen peroxide mouthwash or 0.2% chlorhexidine digluconate mouthwash 1
• Maintain good oral hygiene with a soft toothbrush or swab after meals and before sleep 3

Dietary Modifications

• Avoid potential irritants including smoking, alcohol, spicy foods, citrus fruits, and hot beverages 3

Treatment for Secondary Infections

If candidal infection is suspected (white coating, persistent symptoms):

• Nystatin oral suspension 100,000 units four times daily for 1 week 1, OR
• Miconazole oral gel 5-10 mL held in the mouth after food four times daily for 1 week 1

Second-Line Treatments for Refractory Cases

When first-line treatments fail after 1-2 weeks:

• Tacrolimus 0.1% ointment applied twice daily for 4 weeks 1
• Intralesional triamcinolone injections in conjunction with topical clobetasol 1
• Systemic corticosteroids for highly symptomatic or recurrent ulcers 1

Magic Mouthwash Alternative

For severe cases, consider compounded magic mouthwash:

• Viscous lidocaine 2%, 15 mL per application, held in mouth for 1-2 minutes before spitting out 3
• Avoid eating or drinking for 30 minutes after use for maximum effectiveness 3
• Use alcohol-free formulations to avoid additional irritation 3

Important Clinical Considerations

What NOT to Use

• Oral acyclovir is NOT effective for canker sores (aphthous ulcers), as these are not caused by herpes simplex virus 4
• The evidence from 5 regarding herpes labialis (cold sores) does not apply to canker sores, which are distinct entities 6

When to Escalate Treatment

• Ensure proper diagnosis before initiating treatment, as aphthous ulcers can be confused with herpes simplex virus infections 1
• For patients with recurrent aphthous ulcers, consider underlying systemic conditions (celiac disease, nutritional deficiencies, inflammatory bowel disease) that may require additional treatment 1
• Perform regular oral examinations to monitor effectiveness and detect secondary infections 3

Duration of Effect

• Benzocaine-containing products provide temporary anesthetic relief, with duration varying by formulation 7
• Most canker sores are self-limiting and heal within 7-14 days with appropriate treatment 1