What is the appropriate treatment for a 5-year-old child with a typical herpes simplex virus type 1 lesion on the cheek?

Treatment of HSV on Cheek in a 5-Year-Old Child

For a 5-year-old child with herpes simplex virus type 1 lesions on the cheek, initiate oral acyclovir 20 mg/kg (maximum 400 mg per dose) three times daily for 5-10 days, starting treatment as soon as possible after lesion onset. 1

Dosing and Administration

• Standard pediatric dosing: Acyclovir 20 mg/kg orally three times daily, with a maximum single dose of 400 mg 2, 1
• Treatment duration: Continue for 5-10 days, or until all lesions are completely healed—do not stop at a fixed interval if lesions remain active 1
• The maximum 400 mg dose cap applies to children under 45 kg; children at adult weight can receive standard adult dosing of 400 mg three times daily 1

When to Escalate to IV Therapy

Moderate to severe disease requires intravenous acyclovir:

• If the child has extensive facial involvement, severe pain, or signs of systemic illness, initiate IV acyclovir 5-10 mg/kg three times daily 2, 1
• Once lesions begin to regress on IV therapy, transition to oral acyclovir at the same weight-based dose and continue until complete healing 2, 1
• Critical warning: If there are any signs of CNS involvement (altered mental status, seizures, focal neurologic findings) or disseminated disease, immediately escalate to IV acyclovir 10 mg/kg every 8 hours for 21 days 2, 1

Timing Is Critical

• Initiate treatment immediately at the first sign of lesions or during the prodromal phase (tingling, burning) for maximum benefit 3, 1
• Peak viral titers occur within the first 24 hours after lesion appearance, making early intervention essential to block viral replication 3
• Efficacy decreases substantially when treatment starts after the first 24-48 hours 3

What NOT to Do

• Do not use topical acyclovir—it is substantially less effective than oral therapy and cannot reach the site of viral reactivation 3, 1
• Do not stop treatment at exactly 5 or 7 days if lesions have not fully crusted and healed 1
• Do not delay treatment waiting for laboratory confirmation in typical cases—the clinical diagnosis of grouped vesicles or ulcers on the cheek in a child is sufficient to start therapy 4

Special Considerations for Immunocompromised Children

• If the child is immunocompromised (HIV, chemotherapy, chronic steroids), use higher doses: acyclovir 400 mg orally 3-5 times daily, and consider longer treatment courses 1
• Immunocompromised patients have a 7% risk of acyclovir resistance compared to <0.5% in healthy children 3, 1
• For confirmed acyclovir-resistant HSV (lesions not responding after 7-10 days of appropriate therapy), switch to foscarnet 40 mg/kg IV every 8 hours 2, 1

Infection Control and Contagiousness

• The child remains contagious until all lesions are fully crusted 3
• Avoid direct skin-to-skin contact with the affected area, and do not share towels, utensils, or other items that may contact the lesions 3
• Even with antiviral therapy, viral shedding continues for approximately 6.4 days, so maintain precautions throughout this period 3

When Laboratory Testing Is Needed

• Laboratory confirmation is generally unnecessary for typical recurrent HSV lesions in immunocompetent children 3
• Order HSV PCR or viral culture if:
  • The lesions are atypical, severe, or non-healing 3
  • The child is immunocompromised 4
  • There is concern for CNS involvement or disseminated disease 1

Common Clinical Pitfall

Primary HSV-1 infection in young children often presents as herpetic gingivostomatitis affecting the tongue, lips, gingiva, and palate—not just isolated cheek lesions 4. If the child has extensive oral involvement with fever and difficulty eating, this represents more severe disease requiring the higher end of the treatment duration (10 days) and possibly IV therapy if the child cannot maintain hydration 2, 1.