What treatment is recommended for persistent mouth sores (almost 2 weeks) after exposure to hand, foot, and mouth disease (HFMD)?

Management of Persistent Mouth Sores After Hand, Foot, and Mouth Disease Exposure

For persistent mouth sores (present for almost 2 weeks) following hand, foot, and mouth disease exposure, topical high-potency corticosteroids combined with supportive care including pain management and antiseptic mouthwashes are strongly recommended as first-line treatment.

First-Line Treatment Approach

Topical Corticosteroid Therapy

• For widespread or difficult-to-reach ulcerations:
  • Dexamethasone mouth rinse (0.1 mg/ml) four times daily 1
  • Alternative: Betamethasone sodium phosphate 0.5 mg in 10 mL water as a rinse-and-spit preparation four times daily 1
• For limited, accessible ulcers:
  • Clobetasol gel or ointment (0.05%) applied directly to affected areas 1

Pain Management

• Topical anesthetics for severe pain: Viscous lidocaine 2%, 15 mL per application 1
• Anti-inflammatory oral rinse containing benzydamine hydrochloride every 3 hours, particularly before eating 1
• Mucoprotectant mouthwash (e.g., Gelclair) three times daily 1

Antiseptic Oral Rinses

• 1.5% hydrogen peroxide mouthwash (10 mL) twice daily 1
• 0.2% chlorhexidine digluconate mouthwash (10 mL), can be diluted by up to 50% to reduce soreness 1
• Regular oral cleaning with warm saline mouthwashes 1

Monitoring and Prevention of Secondary Infections

Infection Control

• Monitor for secondary infections and treat accordingly 1
• For suspected candidal infection: Nystatin oral suspension 100,000 units four times daily for 1 week 1
• For suspected bacterial infection: Take oral swabs and treat based on results 1

Hand Hygiene

• Perform hand hygiene with either a nonantimicrobial or antimicrobial soap and water when hands are visibly dirty or contaminated 2
• If hands are not visibly soiled, an alcohol-based hand rub can be used 2

Special Considerations

Disease Course and Expected Resolution

• Hand, foot, and mouth disease is typically self-limiting with lesions usually regressing in two to three weeks 3
• However, persistent lesions beyond the typical timeframe (as in this case) warrant more aggressive treatment
• Nail changes such as shedding may follow HFMD after a latency period 4

Dietary Modifications

• Soft, moist, low-acidity foods during acute ulceration 1
• Adequate hydration is essential 1
• Apply white soft paraffin ointment to lips every 2 hours if affected 1

When to Consider More Aggressive Treatment

If no improvement is seen after 5-7 days of topical therapy, consider:

• Intralesional steroid injection (triamcinolone weekly; total dose 28 mg) in conjunction with topical clobetasol gel/ointment (0.05%) 1
• Short course of systemic corticosteroids for highly symptomatic or recurrent ulcers: High-dose pulse (30-60 mg or 1 mg/kg) oral prednisone/prednisolone for 1 week, followed by dose tapering over the second week 1

Prevention of Transmission

• HFMD is highly contagious and can affect both children and adults 5
• Avoid close contact with infected individuals
• Maintain good hand hygiene practices 2
• Clean and disinfect frequently touched surfaces

Pitfalls and Caveats

• Persistent mouth sores may be mistaken for other conditions such as herpes simplex, herpangina, recurrent aphthae, or erythema multiforme 3
• Atypical manifestations of HFMD in children with atopic dermatitis may mimic herpetic superinfection 4
• While most cases of HFMD are mild and self-limiting, be alert for rare severe complications including pneumonia, meningitis, and encephalitis 5
• Enterovirus 71 strains can cause more severe disease with neurological complications, though this is more common in Asia-Pacific outbreaks 6