Varicella Treatment Recommendations
Healthy Children Under 12 Years
Oral acyclovir is NOT routinely recommended for otherwise healthy children under 12 years with uncomplicated varicella. 1
Rationale for Conservative Approach
- The therapeutic benefit is marginal: acyclovir reduces fever duration by only 1 day and decreases cutaneous/systemic symptoms by 15-30% when initiated within 24 hours of rash onset 1
- Treatment does not reduce acute complications, pruritus, disease transmission, or school absence duration 1
- The cost-benefit ratio remains unfavorable for routine use in this population 1
Supportive Care for Healthy Children
- Symptomatic treatment alone is appropriate for most immunocompetent children, as varicella is typically self-limited, lasting 4-5 days with 250-500 vesicular lesions 2, 3
- Lukewarm baths with colloidal oatmeal can relieve itching 4
- Avoid aspirin due to Reye syndrome risk 3, 5
- Isolate until all lesions have completely crusted (typically 5-7 days after rash onset) 2, 4
High-Risk Populations Requiring Antiviral Therapy
Adolescents (≥13 Years) and Adults
Oral acyclovir should be initiated within 24 hours of rash onset for all otherwise healthy adolescents and adults with varicella. 1, 6
Dosing Regimen
- 800 mg orally 4 times daily for 5 days 7
- Must be started within 24 hours of rash onset; delayed therapy beyond 24 hours results in loss of therapeutic effect 1
Clinical Justification
- Adults are 13 times more likely to be hospitalized than children aged 5-9 years 3
- Case-fatality rate is 25 times higher for adults than children aged 12 months-4 years (21.3 vs 0.8 per 100,000 cases) 3
- Adolescents and adults face significantly higher risk for pneumonia and disseminated disease 4, 2
Immunocompromised Patients
Intravenous acyclovir is indicated for all immunocompromised patients with varicella or herpes zoster. 7, 6
High-Risk Immunocompromised Categories
- HIV infection with CD4 <15% or CD4 <200 cells/µL 5
- Hematologic or solid tumors 5
- Congenital immunodeficiency 5
- Long-term immunosuppressive therapy (≥2 mg/kg/day prednisone or ≥20 mg/day for ≥14 days) 5
Treatment Approach
- Use intravenous acyclovir for severe disease, risk of dissemination, and children <2 years 8
- Initiate treatment at earliest sign of infection 6
- Consider temporary reduction of immunosuppressive medications if clinically feasible 2
- The morbidity and mortality of VZV infections are reduced substantially by early acyclovir treatment 6
Pregnant Women
Pregnant women with varicella require specialized management based on gestational timing and disease severity.
Maternal Treatment
- Oral acyclovir should be considered for pregnant women with varicella, particularly if severe disease develops 8
- Intravenous acyclovir is recommended for severe varicella or pneumonia during pregnancy 8
Post-Exposure Prophylaxis
- VZV-susceptible pregnant women exposed to varicella should receive Varicella-Zoster Immune Globulin (VZIG) within 96 hours of exposure 2
- VZIG administration window extends up to 10 days post-exposure 5
Congenital Varicella Syndrome Risk
- Maternal varicella in the first 20 weeks of pregnancy carries a 1.1% overall risk of congenital varicella syndrome 3
- An estimated 44 cases of congenital varicella syndrome occurred annually in the United States during the pre-vaccine era 3
Neonates
Neonates represent a uniquely vulnerable population requiring aggressive intervention.
Risk Stratification
- Infants <1 year are 6 times more likely to be hospitalized than children aged 5-9 years 3
- Neonates have higher case-fatality rates compared to older children 3
Treatment Recommendations
- Early commencement of acyclovir is recommended for newborns during the first 2 weeks of life 8
- Intravenous acyclovir should be used for children <2 years of age 8
- Preterm infants in the neonatal nursery require acyclovir treatment 8
Post-Exposure Prophylaxis
- VZIG is indicated for exposed neonates <28 weeks gestation or <1,000 g, administered within 96 hours of exposure 2
- VZIG should be given to neonates whose mothers develop varicella from 5 days before to 2 days after delivery 2
Special Considerations for Selective Acyclovir Use in Children
Children Who May Benefit from Oral Acyclovir
Consider oral acyclovir (20 mg/kg orally 4 times daily for 5 days, maximum 800 mg per dose) for children >12 months with:
- Chronic cutaneous disorders (risk of exacerbation and secondary bacterial sepsis) 1, 8
- Chronic pulmonary disease (increased risk of severe disease) 1, 8
- Long-term salicylate therapy (though reduced Reye syndrome risk not proven) 1
- Serious cardiopulmonary disease (varicella may exacerbate underlying condition) 8
Dosing for Children
- Children 2 years and older: 20 mg/kg per dose orally 4 times daily (80 mg/kg/day) for 5 days 7
- Children >40 kg: 800 mg 4 times daily for 5 days (adult dose) 7
- Must be initiated within 24 hours of rash onset 7, 1
Post-Exposure Prophylaxis Strategies
Varicella Vaccine for Post-Exposure Prophylaxis
Administer varicella vaccine within 3-5 days of exposure to susceptible individuals to prevent or modify disease. 2, 5
Efficacy Timeline
- Vaccination within 3 days is >90% effective in preventing varicella 5
- Vaccination within 5 days is approximately 70% effective in preventing varicella and 100% effective in modifying severe disease 5
Eligible Recipients
- Susceptible household contacts 4
- Healthcare workers without immunity 2
- Other susceptible individuals without contraindications 3
Varicella-Zoster Immune Globulin (VZIG)
VZIG should be administered within 96 hours (up to 10 days) of exposure to high-risk susceptible individuals. 2, 5
Indications for VZIG
- Pregnant women without immunity 2
- Immunocompromised patients 2
- Neonates <28 weeks gestation or <1,000 g 2
- HIV-infected children and adults after close contact with varicella 2
Critical Pitfalls and Contraindications
Timing Is Everything
- Acyclovir must be initiated within 24 hours of rash onset to be effective 1, 7
- Delay beyond 24 hours results in loss of therapeutic benefit in otherwise healthy individuals 1
Aspirin Avoidance
Route of Administration Matters
- Oral acyclovir is appropriate for healthy adolescents/adults and select high-risk children 7, 1
- Intravenous acyclovir is mandatory for immunocompromised patients, severe disease, and children <2 years 7, 8