What is the appropriate treatment for recurrent minor aphthous ulcers (canker sores) in an otherwise healthy adult?

Treatment for Canker Sores (Recurrent Aphthous Stomatitis)

For recurrent minor aphthous ulcers in healthy adults, begin with sodium bicarbonate mouthwash 4-6 times daily and escalate to topical high-potency corticosteroids if symptoms persist beyond 48-72 hours, reserving systemic corticosteroids only for severe refractory cases. 1

Initial Management (All Patients)

• Start with non-alcoholic sodium bicarbonate mouthwash 4-6 times daily as foundational therapy for all canker sores 1
• Maintain good oral hygiene with gentle brushing to prevent secondary infections 1
• Use barrier preparations such as Gengigel mouth rinse/gel or Gelclair for pain control 1
• Avoid hard, acidic, salty foods, alcohol, carbonated drinks, and toothpastes containing sodium lauryl sulfate 2
• Consume soft, moist, non-irritating foods that are easy to chew and swallow 1

Severity-Based Treatment Algorithm

Mild Symptoms (Small ulcers, minimal pain)

• Continue sodium bicarbonate rinses 4-6 times daily 1, 3
• Add topical anesthetics such as viscous lidocaine 2% for pain management 1, 3
• Apply benzydamine hydrochloride rinse every 3 hours, particularly before eating 1, 3
• Consider antiseptic agents like triclosan as first-line before advancing to corticosteroids 2

Moderate Symptoms (Larger ulcers, significant pain interfering with eating)

• Increase sodium bicarbonate mouthwash frequency up to hourly if necessary 1, 3
• Initiate topical high-potency corticosteroids as primary therapy:
  • Betamethasone sodium phosphate 0.5 mg dissolved in 10 mL water as rinse-and-spit 1-4 times daily 1
  • Fluticasone propionate nasules diluted in 10 mL water twice daily as alternative 1
  • Clobetasol 0.05% ointment mixed in 50% Orabase applied twice daily to localized lesions 1
• Add amlexanox 5% oral paste as topical anti-inflammatory agent 3, 4
• Dexamethasone ointment applied 3 times daily after meals for 5 days has demonstrated significant reduction in ulcer size (7.2 mm² vs 4.3 mm² with placebo) and healing ratio (83% vs 55%) 5

Severe or Recalcitrant Symptoms (Multiple large ulcers, severe pain, non-responsive to topical therapy)

• Use high-potency topical corticosteroids as first-line for highly symptomatic ulcers 1
• Add intralesional triamcinolone injections (total dose 28 mg) in conjunction with topical clobetasol gel/ointment 1, 3
• Escalate to systemic corticosteroids only if topical measures fail:
  • Prednisone/prednisolone 30-60 mg (or 1 mg/kg) daily for 1 week, then taper over second week 1, 3
  • Reserve systemic corticosteroids for severe cases of major aphthous ulcers unresponsive to topical agents 6

Second-Line Therapies for Resistant Cases

• Tacrolimus 0.1% ointment applied twice daily for 4 weeks for recalcitrant cases 1
• Consider systemic immunomodulatory agents only for refractory disease:
  • Colchicine, pentoxifylline, or prednisolone for severe cases 2
  • Thalidomide reserved as alternative to oral corticosteroids due to toxicity and cost 6
  • Other immunosuppressive agents only for Adamantiades-Behçet disease 2

Critical Diagnostic Considerations

Before initiating corticosteroid therapy, rule out oral herpes (HSV), as corticosteroids potentiate HSV infection and are contraindicated 3:

• Oral herpes presents with vesicles that rupture into ulcers, often with prodromal tingling and possible systemic symptoms 3
• Aphthous ulcers appear as solitary or multiple recurrent ulcers with erythematous haloes and yellow/gray floors, without vesicles 4
• If HSV is suspected, initiate antiviral therapy (acyclovir, valacyclovir, or famciclovir) instead of corticosteroids 3

Treat concurrent candidal infections before or during aphthous ulcer therapy:

• Use nystatin oral suspension or miconazole oral gel for candidiasis 1
• Clotrimazole 10 mg troches 5 times daily for 7-14 days is standard for oral candidiasis 7

Additional Supportive Measures

• Use sugarless chewing gum, candy, or salivary substitutes for oral dryness 1
• Apply ice chips or ice pops as needed to numb the mouth temporarily 1
• Drink plenty of water and use lip balm for dry lips 1

Important Clinical Pitfalls

• Monitor response to topical corticosteroids; if no improvement after 2 weeks, escalate to systemic therapy 3
• Topical medications achieve pain relief and reduce ulcer duration but have not been shown to alter recurrence or remission rates 6
• Systemic medications should be reserved for patients unresponsive to topical treatments, as they may represent a select group requiring more aggressive intervention 8
• Consider PFAPA syndrome if recurrent aphthous stomatitis is particularly severe or frequent 1
• Evaluate for Behçet's disease if patient presents with the triad of uveitis, aphthous stomatitis, and genital ulcers 1