What is the recommended management for chicken pox?

Management of Chickenpox

Primary Treatment Approach

For otherwise healthy children under 13 years, supportive care alone is sufficient, while oral acyclovir 800 mg four times daily for 5 days (initiated within 24 hours of rash onset) is recommended for adolescents ≥13 years, immunocompromised patients requiring IV acyclovir 10 mg/kg every 8 hours, and high-risk groups including those with chronic skin/lung disorders or on long-term corticosteroids. 1, 2, 3

Risk-Stratified Treatment Algorithm

Healthy Children (<13 years, >40 kg)

• Supportive care only is the standard approach for immunocompetent children without risk factors 1, 2
• Hygiene measures including bathing and stringent soaks to prevent secondary bacterial infection 4
• Isolation until all lesions have crusted over (typically 5-7 days after rash onset) 2, 3

Children with Risk Factors

• Oral acyclovir 20 mg/kg per dose (maximum 800 mg) four times daily for 5 days for children with chronic cutaneous disorders (e.g., eczema), chronic pulmonary disorders, or those on long-term salicylate therapy 1, 3, 5
• Must be initiated within 24 hours of rash onset for efficacy 2

Adolescents and Adults (≥13 years)

• Oral acyclovir 800 mg four times daily for 5 days if started within 24 hours of rash onset 1, 2, 5
• This population faces significantly higher complication rates with case-fatality rates 21.3 per 100,000 versus 0.8 per 100,000 in young children 2
• Treatment beyond 24 hours loses efficacy 2

Immunocompromised Patients

• Intravenous acyclovir 10 mg/kg every 8 hours for 7-10 days initiated within 24 hours of rash onset 1, 2, 3, 5
• This includes HIV-infected patients, transplant recipients, cancer patients on chemotherapy, and those receiving high-dose corticosteroids 2
• Immediate initiation is critical as this population faces significant risk of dissemination and death without prompt therapy 2

Pregnant Women

• Intravenous acyclovir for serious viral-mediated complications such as pneumonia 2
• Oral acyclovir may be used for increased risk of moderate-to-severe disease 2
• Acyclovir is FDA Category B in pregnancy with reassuring safety data showing no increased birth defect rates 2

Post-Exposure Prophylaxis

Immunocompetent Susceptible Individuals

• Varicella vaccine within 3 days (up to 5 days) of exposure is >90% effective at preventing disease 2, 3
• This is the preferred method for otherwise healthy individuals 2

High-Risk Individuals Who Cannot Receive Vaccine

• Varicella-Zoster Immune Globulin (VZIG) within 96 hours (extended to 10 days per CDC guidelines) of exposure for: 2, 3

  • Immunocompromised patients
  • Pregnant women without evidence of immunity
  • Neonates born to mothers with varicella from 5 days before to 2 days after delivery
  • Premature infants <28 weeks gestation or <1,000 g regardless of maternal immunity

• VZIG dosing: 125 IU/10 kg body weight intramuscularly, maximum 625 IU (five vials); minimum dose 62.5 IU for infants ≤2.0 kg 2

Alternative Prophylaxis When VZIG Unavailable

• Oral acyclovir 10-20 mg/kg (maximum 800 mg) four times daily for 7 days, starting 7-10 days after exposure 1, 3
• If varicella develops despite VZIG, antiviral therapy should be instituted immediately 2

Infection Control Measures

Patient Isolation

• Isolate until all lesions have crusted over, typically 5-7 days after rash onset 2, 3
• Airborne and contact precautions in healthcare settings 2

Healthcare Worker Management

• Furlough unvaccinated healthcare workers without immunity from days 10-21 after exposure 1, 3
• Healthcare workers with 1 dose of vaccine should receive a second dose within 3-5 days of exposure 1
• Those with 2 doses should be monitored daily for fever and rash on days 8-21 post-exposure 1

Vaccination Considerations

Household Contacts

• Vaccinate susceptible household contacts (seronegative for HIV, no history of chickenpox) of immunocompromised patients to prevent transmission 6, 3

HIV-Infected Children

• Varicella vaccine at 12-15 months for HIV-infected children who are asymptomatic and not immunosuppressed 6, 3
• Do not administer to other immunocompromised patients due to risk of disseminated viral infection 6, 3

Timing After VZIG

• Delay varicella vaccination 5 months after VZIG administration 3

Outbreak Control

• Administer first or second dose as appropriate for persons without adequate evidence of immunity 6
• For preschool-aged children in outbreaks, 2-dose vaccination is recommended with second dose given if 3 months have elapsed since first dose 6
• Persons receiving vaccine during outbreak may be readmitted immediately 6
• Exclude unvaccinated persons without immunity for 21 days after onset of rash in last case 6

Critical Pitfalls to Avoid

• Do not initiate oral acyclovir >24 hours after rash onset in most populations as efficacy is lost 2
• Do not use acyclovir prophylactically in otherwise healthy individuals after exposure—vaccination is preferred 2
• Do not rely on antibody titers in patients with nephrotic-range proteinuria or receiving IVIG as they are unreliable 3
• Do not discharge neonates whose mothers developed varicella from 5 days before to 2 days after delivery without VZIG due to high mortality risk 2
• Avoid ibuprofen due to association with severe secondary bacterial infections including necrotizing fasciitis 7

Renal Dosing Adjustments

For patients with renal impairment receiving oral acyclovir 800 mg every 4 hours: 5

• Creatinine clearance >25 mL/min: 800 mg every 4 hours, 5 times daily
• Creatinine clearance 10-25 mL/min: 800 mg every 8 hours
• Creatinine clearance 0-10 mL/min: 800 mg every 12 hours
• Hemodialysis patients: Administer additional dose after each dialysis session 5