What is the treatment for canker sores?

Treatment for Canker Sores

For canker sores (aphthous ulcers), start with topical corticosteroids—specifically betamethasone sodium phosphate 0.5 mg dissolved in 10 mL water as a rinse-and-spit preparation four times daily, or clobetasol propionate 0.05% mixed with Orabase applied directly to localized ulcers. 1, 2

First-Line Treatment Approach

Topical Corticosteroids (Primary Treatment)

• Betamethasone sodium phosphate 0.5 mg dissolved in 10 mL water, used as a 2-3 minute rinse-and-spit preparation one to four times daily 1, 2
• For localized ulcers, apply clobetasol propionate 0.05% mixed in equal amounts with Orabase directly to dried mucosa twice weekly 1, 2
• Alternative: Fluticasone propionate nasules diluted in 10 mL water twice daily 2

Mucoprotectant Barrier Agents

• Gelclair mucoprotectant gel applied three times daily forms a protective coating that reduces pain and promotes healing 1, 2
• These barrier preparations provide symptomatic relief while corticosteroids address inflammation 2

Pain Management

• Benzydamine hydrochloride oral rinse or spray every 3 hours, particularly before eating 1, 3
• For more severe pain, viscous lidocaine 2% (15 mL per application) can be applied 3-4 times daily 1, 3
• Over-the-counter benzocaine products temporarily relieve pain associated with canker sores 4

Oral Hygiene and Supportive Care

• Clean the mouth daily with warm saline mouthwashes to reduce bacterial colonization 1
• Use 0.2% chlorhexidine digluconate mouthwash twice daily as an antiseptic rinse 1, 3
• Avoid crunchy, spicy, acidic foods and hot beverages that can irritate ulcers 3

Treatment for Secondary Infections

If candidal infection is suspected (common with corticosteroid use):

• Nystatin oral suspension 100,000 units four times daily for 1 week 1, 2
• Alternative: Miconazole oral gel 5-10 mL held in mouth after food four times daily for 1 week 1, 2

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, 2
• Intralesional triamcinolone injections (total dose 28 mg weekly) in conjunction with topical clobetasol for persistent ulcers 1, 2
• Amlexanox 5% paste reduces ulcer size, pain duration, and healing time 5

Systemic Therapy for Severe or Recurrent Cases

For highly symptomatic or frequently recurrent ulcers:

• Systemic corticosteroids: High-dose pulse 30-60 mg or 1 mg/kg oral prednisone/prednisolone for 1 week, followed by dose tapering over the second week 1, 2

Important Clinical Pitfalls

• Seek medical attention if symptoms do not improve in 7 days, or if irritation, pain, redness persists or worsens 4
• Many patients confuse canker sores (aphthous ulcers) with cold sores (herpes labialis)—the evidence provided about herpes labialis treatment with antivirals is not applicable to canker sores 6, 7
• Canker sores are self-limiting and many patients require no treatment, but those with painful or recurrent lesions benefit from the interventions above 6
• Consider underlying systemic conditions (celiac disease, nutritional deficiencies, immunodeficiency) in patients with severe recurrent aphthous ulcers 1, 7
• Always perform regular oral examinations to monitor treatment effectiveness and detect secondary infections 3