Treatment for Chickenpox
For uncomplicated chickenpox in immunocompetent individuals, oral acyclovir (800 mg four times daily for 5 days in adults or 20 mg/kg four times daily for 5 days in children) is the recommended treatment, especially when initiated within 24 hours of rash onset. 1, 2
Treatment Recommendations by Patient Population
Immunocompetent Patients
- For healthy children (2 years and older): 20 mg/kg per dose orally 4 times daily (80 mg/kg/day) for 5 days; children over 40 kg should receive the adult dose 1
- For adults and children over 40 kg: 800 mg 4 times daily for 5 days 1
- Treatment is most effective when initiated within 24 hours of rash onset, but may still provide benefit when started within 48 hours 2
- Five days of therapy is sufficient; a 7-day course provides no additional benefit 2
Immunocompromised Patients
- Intravenous acyclovir is indicated for varicella-zoster infections in immunocompromised patients 1
- Treatment should be initiated at the earliest sign or symptom of chickenpox 1
- Intravenous acyclovir has been shown to cause more rapid resolution of illness and fewer complications in immunocompromised children 3
Post-Exposure Prophylaxis
- For susceptible individuals exposed to chickenpox (especially immunocompromised patients), varicella-zoster immune globulin (VZIG) should be administered within 96 hours of exposure 4
- If VZIG is not available, prophylactic treatment with oral acyclovir (10 mg/kg four times a day for 7 days) within 7-10 days of exposure to chickenpox is recommended 4
Special Considerations
Renal Impairment
- Dose adjustment is necessary for patients with renal impairment 1:
- For creatinine clearance >25 mL/min/1.73m²: 800 mg every 4 hours, 5 times daily
- For creatinine clearance 10-25 mL/min/1.73m²: 800 mg every 8 hours
- For creatinine clearance <10 mL/min/1.73m²: 800 mg every 12 hours
Pregnant Women
- VZIG is recommended for VZV-susceptible pregnant women within 96 hours after exposure to VZV 4
- Treatment decisions should be individualized after consultation with a specialist 4
Supportive Care
- Symptomatic treatment is indicated in all immunocompetent patients with no signs of complications 5
- Maintain adequate hydration and urine flow, especially with higher doses of acyclovir 3
- Monitor mental status of patients on high-dose acyclovir therapy 3
Common Pitfalls and Caveats
- Delaying treatment beyond 24 hours after rash onset significantly reduces the effectiveness of antiviral therapy 2
- There is no evidence that acyclovir treatment prevents the establishment of latent infection that may later reactivate as herpes zoster (shingles) 3
- Adequate hydration must be maintained during acyclovir treatment to prevent renal complications 3
- For patients requiring hemodialysis, an additional dose of acyclovir should be administered after each dialysis session 1
Infection Control Measures
- Patients with chickenpox require airborne and contact precautions until all lesions are dry and crusted 6
- Only healthcare personnel with evidence of immunity to varicella should care for patients with confirmed or suspected varicella 6
- Household contacts of susceptible individuals should be vaccinated against VZV if they have no history of chickenpox and are seronegative for HIV 6
The evidence clearly shows that early initiation of antiviral therapy provides the greatest benefit in reducing the severity and duration of chickenpox symptoms, with a 5-day course being optimal for most patients 2.