What is the treatment for aphthous ulcers (canker sores)?

Treatment of Canker Sores (Aphthous Ulcers)

Start with topical corticosteroids as first-line therapy, specifically clobetasol gel 0.05% applied directly to dried ulcers twice daily for localized lesions, or betamethasone sodium phosphate 0.5 mg dissolved in 10 mL water as a rinse-and-spit solution four times daily for multiple or widespread ulcers. 1, 2

First-Line Topical Corticosteroid Therapy

The most effective initial approach uses potent topical steroids:

• For localized ulcers: Apply clobetasol 0.05% ointment mixed in 50% Orabase directly to dried lesions 2-4 times daily 1, 2
• For multiple or widespread ulcers: Use betamethasone sodium phosphate 0.5 mg in 10 mL water as rinse-and-spit four times daily 1, 2
• Alternative option: Triamcinolone acetonide 0.1% paste applied directly to dried ulcer 2-4 times daily 1
• Another alternative: Fluticasone propionate nasules diluted in 10 mL water twice daily 2

Pain Management (Essential for Maintaining Oral Intake)

Aggressive pain control should be implemented immediately:

• Benzydamine hydrochloride rinse or spray every 3 hours, particularly before meals 1, 2
• Viscous lidocaine 2% applied topically 3-4 times daily for severe pain 1, 2, 3
• Barrier preparations such as Gelclair or Gengigel mouth rinse applied three times daily for mucosal protection 1, 2
• Topical benzocaine products (e.g., Red Cross Canker Sore Medication, Anbesol, Orajel) provide temporary pain relief 3, 4

Supportive Oral Hygiene Measures

Daily oral care reduces bacterial colonization and promotes healing:

• Clean mouth daily with warm saline mouthwashes 1, 2
• Use antiseptic oral rinses twice daily: 0.2% chlorhexidine digluconate mouthwash or 1.5% hydrogen peroxide 1, 2
• Apply white soft paraffin ointment to lips every 2 hours if lips are affected 1
• For dry mouth: Recommend sugarless chewing gum, candy, or salivary substitutes 1

Second-Line Treatment for Refractory Cases (Not Responding After 1-2 Weeks)

If topical therapy fails after 1-2 weeks of treatment:

• Intralesional triamcinolone injections weekly (total dose 28 mg) for persistent localized ulcers 1, 2
• Tacrolimus 0.1% ointment applied twice daily for 4 weeks as an alternative to triamcinolone 1, 2
• Systemic corticosteroids: Prednisone/prednisolone 30-60 mg (or 1 mg/kg) for 1 week with tapering over the second week for highly symptomatic or recurrent ulcers 1, 2

Third-Line Systemic Therapy for Severe Recurrent Cases

For patients with frequent recurrences despite topical and intralesional therapy:

• Colchicine as first-line systemic therapy, especially effective for recurrent aphthous stomatitis with erythema nodosum or genital ulcers 5, 1, 2
• Azathioprine, interferon-alpha, or TNF-alpha antagonists for resistant cases 5, 1, 2
• Apremilast may be considered in selected cases 1

Critical Red Flags Requiring Specialist Referral

Refer to a specialist immediately if:

• Ulcers persist beyond 2 weeks 1, 2
• Ulcers do not respond to 1-2 weeks of treatment 1, 2
• Biopsy is indicated to exclude malignancy in these cases 1

Common Pitfalls to Avoid

• Do not prematurely taper corticosteroids before disease control is established 1, 2
• Do not ignore potential underlying systemic conditions such as Behçet's disease, inflammatory bowel disease, celiac disease, or immunodeficiency states that may require additional treatment 5, 2, 6
• If ulcers developed after starting an NSAID (like meloxicam/Mobic), stop the medication immediately as NSAIDs are well-documented to cause oral ulcerations 7
• Perform blood tests (full blood count, coagulation, fasting glucose, HIV antibody, syphilis serology) before biopsy to exclude contraindications and provide diagnostic clues 1

Dietary Modifications During Active Ulceration

• Recommend soft, moist foods served at room temperature or cold to minimize pain during eating 7