What is the initial treatment for aphthous (canker sore) ulcers?

Initial Treatment for Aphthous (Canker Sore) Ulcers

Start with topical corticosteroids as first-line therapy, combined with topical anesthetics for pain control and antiseptic rinses for oral hygiene. 1, 2, 3

First-Line Topical Corticosteroid Options

The cornerstone of initial management is topical corticosteroid therapy, with selection based on ulcer location and extent 1, 2:

For localized, accessible ulcers:

• Apply clobetasol 0.05% ointment mixed in 50% Orabase directly to dried mucosa twice weekly 1, 2, 3
• Alternatively, use triamcinolone acetonide 0.1% paste applied directly to dried ulcer 2-4 times daily 1

For multiple or widespread ulcers:

• Use betamethasone sodium phosphate 0.5 mg dissolved in 10 mL water as a rinse-and-spit solution 2-4 times daily 1, 2, 3
• Alternative option: fluticasone propionate nasules diluted in 10 mL water twice daily 2, 3

The evidence supporting topical corticosteroids comes from multiple high-quality guidelines, though the underlying research quality is low 4, 5. Despite this, they remain the standard of care based on extensive clinical experience and expert consensus.

Pain Management (Essential Component)

Pain control is critical for maintaining quality of life during healing 1, 2:

Topical anesthetics:

• Apply benzydamine hydrochloride rinse or spray every 3 hours, particularly before eating 1, 2
• For more severe pain, use viscous lidocaine 2% (15 mL per application) 3-4 times daily 1, 2

Barrier preparations for mucosal protection:

• Apply Gelclair or Gengigel three times daily to protect ulcerated surfaces 1, 2, 3
• Use white soft paraffin ointment to lips every 2 hours 1

One study suggested topical anesthetics may be more effective than corticosteroids alone (49% effectiveness), though this was a single retrospective analysis 6. The guideline consensus recommends using both concurrently rather than choosing one over the other.

Oral Hygiene and Antiseptic Measures

Maintaining oral hygiene reduces bacterial colonization and secondary infection risk 1, 2:

• Clean mouth daily with warm saline mouthwashes 1, 2
• Use antiseptic oral rinses twice daily: either 1.5% hydrogen peroxide or 0.2% chlorhexidine digluconate (10 mL) 1, 2
• Dilute chlorhexidine by up to 50% if it causes excessive soreness 7

Treatment Algorithm for Non-Responders

If ulcers persist after 1-2 weeks of topical therapy 1:

1. Add tacrolimus 0.1% ointment applied twice daily for 4 weeks 2, 3
2. Consider intralesional triamcinolone injections weekly (total dose 28 mg) in conjunction with topical clobetasol 1, 2, 3
3. For highly symptomatic or recurrent cases: systemic corticosteroids (prednisone/prednisolone 30-60 mg or 1 mg/kg for 1 week, tapering over second week) 1, 2, 3

For recurrent aphthous stomatitis (≥4 episodes per year):

• Start colchicine as first-line systemic therapy, especially effective if patient also has erythema nodosum or genital ulcers 1, 2, 8, 5

Critical Pitfalls to Avoid

• Do not taper corticosteroids prematurely before disease control is established 1
• Avoid sodium lauryl sulfate-containing toothpastes, hard/acidic/salty foods, alcohol, and carbonated drinks 5
• Refer to specialist if ulcers persist >2 weeks or don't respond to 1-2 weeks of treatment to rule out malignancy or systemic disease 1, 9
• Screen for secondary candidal infection if healing is slow; treat with nystatin oral suspension 100,000 units four times daily for 1 week or miconazole oral gel 5-10 mL four times daily 7, 2, 3

What NOT to Use

Avoid growth factors, autologous platelet gels, bioengineered skin products, ozone, topical carbon dioxide, or nitric oxide as these have not demonstrated benefit over standard care 7.