What is the recommended treatment for cold sores (herpes simplex labialis) in children?

Treatment for Cold Sores in Children

For children with cold sores (herpes simplex labialis), oral acyclovir at a dose of 20 mg/kg body weight (maximum 400 mg/dose) three times daily for 5-10 days is the recommended first-line treatment. 1

Treatment Algorithm Based on Severity

Mild Symptomatic Cold Sores

• First-line: Oral acyclovir, 20 mg/kg body weight (maximum 400 mg/dose) per dose orally three times daily for 5-10 days 1
• Start treatment at the earliest sign of symptoms for maximum effectiveness
• For children 12 years and older, topical penciclovir cream can be used as an alternative, applied every 2 hours while awake for 4 consecutive days 2, 3

Moderate to Severe Symptomatic Cold Sores

• First-line: Intravenous acyclovir, 5-10 mg/kg body weight per dose three times daily 1
• Once lesions begin to regress, switch to oral acyclovir and continue therapy until lesions completely heal 1

Treatment Considerations by Age

Children Under 12 Years

• Oral acyclovir remains the mainstay of treatment due to established pediatric dosing
• No FDA-approved topical antiviral preparations specifically for children under 12 years

Children 12 Years and Older

• Can use adult formulations including:
  • Oral acyclovir as described above
  • Topical penciclovir cream (FDA approved for ages 12+) 2
  • For older children who can receive adult dosing, valacyclovir or famciclovir may be considered, though pediatric data are limited 1

Supportive Care Measures

• Pain management: Age-appropriate analgesics (acetaminophen or ibuprofen)
• Hydration: Encourage fluid intake to prevent dehydration, especially if oral lesions are painful 4
• Nutrition: Offer soft, non-acidic foods that won't irritate lesions 4
• Skin care: Keep the area clean and dry to prevent secondary bacterial infection 4
• Moisturizing: Apply white soft paraffin ointment to prevent cracking and bleeding of crusted lesions 4

Important Clinical Considerations

• Treatment is most effective when started within the first 24-48 hours of symptom onset 4, 5
• Valacyclovir has better bioavailability than acyclovir and may be more effective in older children who can take adult doses, but lacks established pediatric dosing 1, 5
• For immunocompromised children, higher doses and longer treatment duration may be necessary 4
• For acyclovir-resistant HSV infection, intravenous foscarnet (40 mg/kg body weight per dose three times daily) is recommended 1

Prevention of Recurrence and Spread

• Avoid known triggers including UV radiation, fever, and local trauma 4
• Use sunscreen (SPF 15+) to prevent UV-triggered recurrences 4
• Teach children not to touch or pick at lesions to prevent autoinoculation and spread 6
• Avoid sharing personal items like towels, utensils, or lip products 6
• Wash hands frequently, especially after touching the affected area 6

Follow-up Recommendations

• Follow up within 7-10 days if:
  • Symptoms worsen
  • No improvement after 72 hours of treatment
  • New symptoms develop
  • The child is immunocompromised 4

Treatment of cold sores in children should focus on early intervention with appropriate antiviral therapy based on the child's age and the severity of symptoms, with oral acyclovir being the cornerstone of treatment for most pediatric patients.