Management of Canker Sores (Aphthous Ulcers) in Infants
For true aphthous ulcers in infants, start with oral acetaminophen for pain control and benzydamine hydrochloride spray before feeds, while avoiding topical corticosteroids unless you've ruled out infectious causes—but first, you must distinguish true aphthous ulcers from the more common Bednar's aphthae, which are mechanically-induced palatal ulcers that resolve spontaneously with feeding position correction. 1, 2
Critical First Step: Distinguish Bednar's Aphthae from True Aphthous Ulcers
Bednar's aphthae are the most common "canker sore-like" lesions in infants and require completely different management:
- Location matters: Bednar's aphthae appear as shallow, symmetrical ulcers on the posterior hard palate in infants aged 2 days to 6 weeks 3, 2
- Mechanical cause: These result from pressure during feeding—particularly bottle-feeding in a horizontal position 2
- Self-limited: They resolve spontaneously within 1 month once feeding position is corrected 2
- No medication needed: Simply educate parents to feed in a semi-seated position rather than horizontal 2
When It's Actually Aphthous Ulceration
True aphthous ulcers are uncommon in infants but can occur. If the ulcer is NOT on the posterior palate or doesn't fit Bednar's pattern:
Immediate Pain Management
- Administer oral acetaminophen at age-appropriate dosing for systemic pain relief 1
- Apply benzydamine hydrochloride spray every 3 hours, particularly before feeds to facilitate eating 1
- Use topical 2.5% lidocaine ointment cautiously—limit frequency and amount due to systemic absorption risk in infants 4, 1
- Apply white soft paraffin ointment to lips every 2 hours if lesions involve the lips 1
Supportive Care
- Clean mouth daily with warm saline mouthwashes to reduce bacterial colonization 1
- Apply mucoprotectant preparations (such as barrier gels) three times daily 1
- Consider nasogastric feeding if oral intake is severely compromised to avoid ulcer irritation 3
When to Use Topical Corticosteroids
Critical caveat: Topical steroids should ONLY be used after ruling out infectious causes (viral, bacterial, fungal), as they can worsen infections. 1
If the ulcer is confirmed non-infectious:
- For localized ulcers: Apply triamcinolone acetonide 0.1% paste directly to dried ulcer 2-4 times daily 1, 5
- For multiple or widespread ulcers: Use betamethasone sodium phosphate 0.5 mg dissolved in 10 mL water as rinse-and-spit solution 2-4 times daily 1, 5
Red Flags Requiring Specialist Referral
- Ulcer persists beyond 2 weeks
- No response to 1-2 weeks of appropriate treatment
- Systemic symptoms present (fever, poor feeding, lethargy)
- Multiple recurrent episodes suggesting underlying systemic disease
Investigate for Underlying Conditions in Recurrent Cases
- Nutritional deficiencies (iron, folate, B12) 6
- Gastrointestinal disorders (celiac disease, inflammatory bowel disease) 6
- Immunologic abnormalities (HIV, neutropenia) 6
- PFAPA syndrome (periodic fever, aphthous stomatitis, pharyngitis, adenopathy)—consider if ulcers coincide with periodic fever episodes 7
Common Pitfalls to Avoid
- Don't use topical corticosteroids for suspected viral infections (especially herpes simplex)—this worsens the condition 1
- Don't assume all infant oral ulcers are aphthous—Bednar's aphthae are far more common and require only feeding position correction 2
- Don't use systemic corticosteroids prematurely—rarely needed in simple cases and can mask serious underlying conditions 1, 5
- Don't overlook feeding difficulties—infants with oral ulcers may have reduced intake requiring close monitoring of hydration and weight 3
- Don't forget to educate parents on monitoring—they should report rapid growth, bleeding, or development of new lesions 1