What treatment is recommended for a patient with a canker sore after hitting their mouth?

Treatment of Traumatic Canker Sore

For a canker sore caused by mouth trauma, start with benzydamine hydrochloride oral rinse or spray every 2-4 hours for pain control, combined with warm saline mouthwashes and white soft paraffin ointment to the lips every 2 hours. 1

First-Line Pain Management

• Benzydamine hydrochloride (anti-inflammatory oral rinse/spray) should be used every 2-4 hours, particularly before eating, as it provides both anti-inflammatory and analgesic effects for oral mucosal lesions 2, 1
• If benzydamine provides inadequate pain control, viscous lidocaine 2% (15 mL per application) can be used as an alternative topical anesthetic 2, 1
• Over-the-counter benzocaine-containing products provide anesthetic relief, though patients should discontinue use if symptoms don't improve within 7 days 3, 4

Essential Supportive Care

• Daily warm saline mouthwashes reduce bacterial colonization and promote healing 2, 1
• White soft paraffin ointment should be applied to the lips every 2 hours to prevent cracking and provide a protective barrier 2, 1
• Mucoprotectant mouthwashes (such as Gelclair) can be used three times daily to protect ulcerated surfaces and provide symptomatic relief 2, 1

Antiseptic Rinses to Prevent Secondary Infection

• 0.2% chlorhexidine digluconate mouthwash (10 mL twice daily) or 1.5% hydrogen peroxide mouthwash can be used to reduce bacterial colonization 2, 1
• Diluting chlorhexidine by up to 50% reduces soreness that can accompany treatment 2
• If candidal infection develops (prolonged healing, white patches), treat with nystatin oral suspension or miconazole oral gel 2, 1, 5

Escalation for Severe or Persistent Ulcers

• For ulcers not improving within 7-10 days, consider betamethasone sodium phosphate 0.5 mg in 10 mL water as a 2-3 minute rinse-and-spit solution 1-4 times daily 2, 5
• For localized lesions, clobetasol 0.05% ointment mixed in 50% Orabase can be applied twice daily to dried mucosa 5
• If topical corticosteroids are insufficient, tacrolimus 0.1% ointment applied twice daily for 4 weeks can be considered for recalcitrant ulcers 5

Common Pitfalls to Avoid

• Do not use sucralfate mouthwash for canker sores, as strong evidence indicates lack of effectiveness 2
• Avoid chlorhexidine as a preventive measure in radiation-induced mucositis, though it remains useful for managing bacterial colonization in traumatic canker sores 2, 1
• Ensure adequate antimicrobial coverage before adding topical corticosteroids if secondary infection is suspected 6
• Monitor for signs of secondary HSV infection (slow healing) or candidiasis, particularly if using corticosteroid therapy 2, 5

When to Reassess

• If symptoms don't improve within 7 days despite treatment, reassess for underlying causes or secondary infection 3
• Persistent or recurrent ulcers warrant evaluation for systemic disease, nutritional deficiencies (hematinic deficiency in up to 20% of cases), or medication-related causes 7, 8