What is the recommended treatment for varicella?

Treatment of Varicella (Chickenpox)

Acyclovir is the recommended treatment for varicella, with dosing regimens varying based on patient age, immune status, and disease severity. 1, 2

Treatment Recommendations by Patient Population

Immunocompetent Children

• For children 2 years and older: Oral acyclovir 20 mg/kg per dose 4 times daily (80 mg/kg/day) for 5 days, not to exceed 800 mg per dose 2
• For children over 40 kg: Adult dosing of 800 mg 4 times daily for 5 days 2
• Treatment should be initiated at the earliest sign or symptom of chickenpox, preferably within 24 hours of rash onset 2, 3
• Early treatment with acyclovir has been shown to reduce fever duration, accelerate cutaneous healing, and decrease the number of lesions 3

Immunocompetent Adults

• Oral acyclovir 800 mg 4 times daily for 5 days 2
• Treatment is most effective when started within 24 hours of rash onset 1
• Acyclovir has been demonstrated to reduce the duration and severity of clinical illness in adults 1

Immunocompromised Patients

• Intravenous acyclovir is indicated for immunocompromised patients with varicella 2, 4
• The recommended dose is 10 mg/kg or 500 mg/m² every 8 hours for 7-10 days 4, 5
• IV acyclovir has been shown to decrease new lesion formation, reduce acute pain, halt dissemination, and lessen visceral complications in immunocompromised patients 6, 5
• Treatment should be initiated immediately upon diagnosis, as early treatment is essential for preventing serious complications 5

Special Populations

Pregnant Women

• For pregnant women with serious varicella complications (e.g., pneumonia), intravenous acyclovir should be considered 1
• Acyclovir is classified as a Category B drug in pregnancy 1
• A registry of 596 infants whose mothers received systemic acyclovir during first trimester showed no increased rate of birth defects 1

Neonates and Premature Infants

• For neonates whose mothers developed varicella from 5 days before to 2 days after delivery: Varicella-Zoster Immune Globulin (VZIG) is indicated 1
• For premature infants born at <28 weeks gestation or weighing <1,000g with postnatal exposure: VZIG regardless of maternal immunity 1
• For premature infants born at >28 weeks gestation with postnatal exposure whose mothers lack immunity: VZIG is indicated 1

Post-Exposure Prophylaxis

Immunocompromised Patients

• VZIG is recommended for post-exposure prophylaxis in immunocompromised patients without evidence of immunity 1
• Dosage: 125 units/10 kg of body weight, up to maximum of 625 units 1
• VZIG should be administered as soon as possible after exposure, ideally within 96 hours 1
• Patients receiving monthly high-dose IGIV (>400 mg/kg) within 3 weeks before exposure likely don't require VZIG 1

Healthy Individuals

• Acyclovir is not indicated for prophylactic use among otherwise healthy individuals after exposure 1
• Vaccination is the method of choice for post-exposure prophylaxis in healthy individuals without evidence of immunity 1

Important Clinical Considerations

• Treatment with acyclovir should be initiated within 24 hours of rash onset for maximum effectiveness 1, 2
• Acyclovir does not decrease transmission of varicella or reduce the duration of absence from school 1
• Adequate hydration and urine flow must be maintained during treatment, especially with high-dose IV therapy 6
• For patients with renal impairment, dose adjustment is necessary based on creatinine clearance 2
• Patients receiving hemodialysis require an additional dose after each dialysis session 2
• Acyclovir-resistant VZV strains may emerge in immunocompromised patients; foscarnet is the treatment of choice in such cases 7

Monitoring During Treatment

• Monitor mental status of patients receiving high-dose IV therapy 6
• For immunocompromised patients, monitor for progression of cutaneous dissemination and development of visceral complications 5
• In patients with renal impairment, monitor renal function during treatment 2

By following these evidence-based treatment recommendations, the morbidity and mortality associated with varicella infections can be significantly reduced, particularly in high-risk populations.