What is the recommended treatment for an 11-year-old patient with herpes simplex virus (HSV) infection?

Treatment of Herpes Simplex Virus in an 11-Year-Old

For an 11-year-old with herpes simplex virus infection, oral acyclovir 20 mg/kg (maximum 400 mg) three times daily for 5-10 days is the recommended treatment, with the specific duration and route depending on the severity and location of infection. 1

Treatment Based on Clinical Presentation

Mild Mucocutaneous HSV (Gingivostomatitis, Cold Sores, or Genital Herpes)

• Oral acyclovir 20 mg/kg (maximum 400 mg per dose) three times daily for 5-10 days is the standard treatment for children under 45 kg 1
• Treatment should be initiated at the first sign of symptoms or during the prodrome stage for maximum benefit 2, 3
• For mild symptomatic gingivostomatitis specifically, this same dosing continues until lesions completely heal 1

Moderate to Severe Mucocutaneous Disease

• Intravenous acyclovir 5-10 mg/kg three times daily should be initiated for moderate to severe symptomatic gingivostomatitis or extensive disease 1
• Once lesions begin to regress, transition to oral acyclovir at the same weight-based dosing (20 mg/kg three times daily) and continue until complete healing 1
• This approach is particularly important for immunocompromised children or those with severe primary infections 4, 5

CNS or Disseminated HSV Disease

• Intravenous acyclovir 10 mg/kg three times daily for 21 days is required for CNS involvement or disseminated disease in children outside the neonatal period 1
• This represents a critical distinction from mucocutaneous disease, as CNS involvement carries significant morbidity and mortality risk 1
• Earlier initiation of therapy (within 4 days of symptom onset) significantly reduces mortality from 28% to 8% 1

Important Clinical Considerations

Dosing Pitfalls

• The maximum dose of 400 mg per administration applies to children weighing less than 45 kg 1
• Children who have reached adult weight (≥45 kg) or are postpubertal can receive adult dosing of acyclovir 400 mg three times daily 1
• Do not use topical acyclovir as it is substantially less effective than oral formulations 1, 3

Duration of Therapy

• For genital herpes in children, treatment duration is 5-14 days depending on severity 1
• For orolabial lesions, 7-10 days is standard, though 5-10 days is acceptable for milder cases 3
• Treatment should continue until lesions completely heal, not just for a fixed number of days 1

Alternative Agents (Limited Pediatric Data)

• Valacyclovir and famciclovir are approved for adults and adolescents but lack pediatric formulations and dosing data for younger children 1
• These agents could be considered for older children (postpubertal) who can swallow adult-sized tablets and receive adult dosing 1, 4
• Valacyclovir 1 gram twice daily or famciclovir 250 mg three times daily are adult doses that may apply to postpubertal adolescents 2

Acyclovir Resistance

• Suspect resistance if lesions do not begin healing after 7-10 days of appropriate acyclovir therapy 2, 3
• For proven or suspected acyclovir-resistant HSV, foscarnet 40 mg/kg IV every 8 hours (or 60 mg/kg twice daily) is the treatment of choice 1
• Resistance is more common in immunocompromised patients receiving chronic suppressive therapy 1

Special Populations

• Immunocompromised children may require higher doses (acyclovir 400 mg orally 3-5 times daily) and longer treatment courses 6
• Neonates require different dosing (20 mg/kg IV every 8 hours for 21 days for CNS disease) and are not covered by the standard pediatric recommendations 1

Prevention Counseling

• Patients should avoid close contact when lesions or prodromal symptoms are present 1, 2, 3
• For adolescents with genital herpes, latex condoms should be used during every sexual act to reduce transmission risk 1, 2
• Asymptomatic viral shedding can occur and lead to transmission even without visible lesions 2, 3