What is the recommended treatment for chickenpox?

Treatment of Chickenpox

The recommended treatment for chickenpox is oral acyclovir at a dose of 20 mg/kg body weight (maximum 800 mg/dose) 4 times daily for 5 days, ideally started within the first 24 hours of rash onset. 1

Treatment Recommendations by Population

Immunocompetent Patients

• For children less than 40 kg: Acyclovir 20 mg/kg per dose orally 4 times daily (80 mg/kg/day) for 5 days 2
• For adults and children over 40 kg: Acyclovir 800 mg orally 4 times daily for 5 days 2
• Treatment should be initiated at the earliest sign or symptom of chickenpox, ideally within 24 hours of rash onset for maximum effectiveness 1, 3
• Five days of therapy is sufficient as studies have shown that a 7-day course provides no additional benefit 3

Immunocompromised Patients

• Intravenous acyclovir is recommended for immunocompromised patients at a dose of 10 mg/kg IV every 8 hours 1
• Some experts base IV acyclovir dosing in children over 1 year on body surface area (500 mg/m²/dose IV every 8 hours) 1
• Treatment duration for immunocompromised patients should be 7-10 days or until no new lesions appear for 48 hours 1

Special Populations Requiring Treatment

• Adults (especially those over 12 years of age) 1
• Patients with chronic cutaneous or pulmonary disorders 1
• Patients receiving long-term salicylate therapy 1
• Patients receiving corticosteroids (even short, intermittent, or aerosolized courses) 1
• Secondary household contacts of infected children 1
• Pregnant women (with consultation regarding risks/benefits) 1

Post-Exposure Prophylaxis

• For susceptible immunocompromised patients exposed to chickenpox, varicella zoster immune globulin (VZIG) should be administered within 96 hours of exposure 4, 1
• 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 can be considered 5, 4
• Acyclovir is not routinely indicated for prophylactic use in healthy individuals after exposure to varicella 1

Dosage Adjustments for Renal Impairment

• For patients with renal impairment receiving 800 mg every 4 hours: 2
  • Creatinine clearance >25 mL/min/1.73m²: 800 mg every 4 hours, 5x daily
  • Creatinine clearance 10-25 mL/min/1.73m²: 800 mg every 8 hours
  • Creatinine clearance 0-10 mL/min/1.73m²: 800 mg every 12 hours
• For hemodialysis patients: An additional dose should be administered after each dialysis session 2

Clinical Pearls and Pitfalls

• Early treatment (within 24 hours of rash onset) is crucial for maximizing the effectiveness of antiviral therapy 6, 3
• Acyclovir does not eradicate latent virus or affect subsequent risk, frequency, or severity of recurrences 1
• Antibody titers after infection in children receiving acyclovir do not differ substantially from those not receiving treatment 1
• Studies have shown that viruses shed during therapy remain susceptible to acyclovir and retain normal thymidine kinase function 3
• Symptomatic treatment alone is usually adequate for uncomplicated chickenpox in immunocompetent children, but antiviral therapy should be considered for those at higher risk of complications 7
• Adults are at higher risk for complications of chickenpox, particularly pneumonia, which occurs in approximately 1 in 400 adults with chickenpox 8, 9

Supportive Care

• Antipyretics for fever (avoid aspirin due to risk of Reye syndrome) 9
• Antihistamines or topical calamine lotion to reduce itching 9
• Maintaining good hygiene to prevent secondary bacterial infections 7
• Adequate hydration 9

By following these treatment guidelines, the risk of complications from chickenpox can be significantly reduced, particularly in high-risk populations such as adults and immunocompromised patients.