What is the best treatment approach for a patient presenting with canker sores?

Treatment of Canker Sores (Aphthous Ulcers)

For canker sores, start with topical corticosteroid rinses—specifically betamethasone sodium phosphate 0.5 mg dissolved in 10 mL water used as a 2-3 minute rinse-and-spit four times daily, combined with benzydamine hydrochloride spray every 3 hours for pain control. 1, 2

First-Line Treatment Approach

Topical Corticosteroids (Primary Treatment)

• Betamethasone sodium phosphate 0.5 mg in 10 mL water is the cornerstone treatment: hold in mouth for 2-3 minutes, then spit out, use 1-4 times daily 3, 1, 2
• Alternative: Fluticasone propionate nasules diluted in 10 mL water twice daily 1
• For localized ulcers: Clobetasol 0.05% ointment mixed 1:1 with Orabase applied directly to dried mucosa twice daily 1, 2

Pain Management (Essential Adjunct)

• Benzydamine hydrochloride oral rinse or spray every 3 hours, especially before eating 3, 2, 4
• For severe pain: Viscous lidocaine 2%, 15 mL per application, up to 3-4 times daily 3, 2, 4
• Gelclair mucoprotectant gel three times daily forms a protective barrier over ulcers 2

Oral Hygiene Measures

• Warm saline mouthwashes daily to reduce bacterial colonization 3, 2
• 0.2% chlorhexidine digluconate mouthwash 10 mL twice daily (can dilute by 50% to reduce stinging) 3, 2
• Alternative: 1.5% hydrogen peroxide mouthwash 10 mL twice daily 3, 2

Second-Line Treatment 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 (total dose 28 mg weekly) combined with topical clobetasol 0.05% 1, 2

Systemic Therapy for Severe or Recurrent Disease

For Highly Symptomatic or Recurrent Ulcers

• Prednisone/prednisolone 30-60 mg (or 1 mg/kg) daily for 1 week, followed by tapering over the second week 1, 4

For Recurrent Aphthous Stomatitis

• Colchicine is particularly effective for recurrent disease, especially when associated with Behçet disease 3, 1
• Azathioprine 2.5 mg/kg/day for severe cases with frequent recurrences 3, 1
• Thalidomide is the most effective treatment but limited by teratogenicity and peripheral neuropathy risks 3, 1

Treatment of Secondary Infections

Critical caveat: Always check for and treat concurrent infections before or during corticosteroid use. 2, 4

• If candidal infection suspected: Nystatin oral suspension 100,000 units four times daily for 1 week 3, 2
• Alternative: Miconazole oral gel 5-10 mL held in mouth after food four times daily for 1 week 3, 2

Common Pitfalls to Avoid

• Do not use corticosteroid rinses if active infection is present—treat candidiasis first or concurrently 4
• For posterior oral/tonsillar lesions, avoid lozenges (choking hazard); use rinses or sprays instead 4
• Slow healing may indicate HSV reactivation requiring antiviral therapy 3
• Dilute chlorhexidine by 50% if it causes excessive soreness 3

Alternative Evidence-Based Options

Low-level laser therapy shows promise in research studies, with significant pain reduction and faster healing (3 days vs 9 days) compared to topical triamcinolone 5, 6. However, this requires specialized equipment and is not included in major guidelines as first-line therapy.