What are the management options for chicken pox?

Management of Chickenpox

For immunocompetent children and adults with chickenpox, initiate oral acyclovir within 24 hours of rash onset at 20 mg/kg (maximum 800 mg) four times daily for 5-7 days to reduce disease severity, duration of fever, and time to healing. 1, 2

Antiviral Treatment Indications

Acyclovir therapy is specifically recommended for:

• All patients over 12 years of age due to increased disease severity with age 1, 3
• Immunocompromised individuals (require intravenous acyclovir 10 mg/kg IV every 8 hours) 1, 4
• Patients with chronic cutaneous or pulmonary disorders 1
• Those receiving long-term salicylate or corticosteroid therapy 1
• Secondary and tertiary household cases (tend to be more severe than primary cases) 3

Dosing Regimens

Oral Therapy (Mild-Moderate Disease)

• Children <45 kg: 20 mg/kg (maximum 400 mg/dose) 3-4 times daily for 5-10 days 1
• Adults and adolescents: 800 mg orally 4-5 times daily for 7-10 days 1, 2
• Critical timing: Must initiate within 24 hours of rash onset for maximum efficacy 2, 5

Intravenous Therapy (Severe Disease)

• Immunocompromised or severe cases: 10 mg/kg IV every 8 hours 1, 3
• Discontinue immunomodulator therapy if possible in severe cases 1

Post-Exposure Prophylaxis

High-Risk Individuals

Varicella-Zoster Immune Globulin (VZIG) is the first-line prophylaxis and must be administered within 96 hours of exposure for: 6

• Pregnant women (prevents maternal complications, not fetal infection) 6
• Immunocompromised patients 6
• Premature infants <28 weeks gestation or <1,000 g (regardless of maternal immunity) 6
• Neonates born to mothers with varicella from 5 days before to 2 days after delivery 6

Important caveat: VZIG may prolong the incubation period to 28 days, requiring extended monitoring 6, 4

Alternative Prophylaxis

If VZIG is unavailable or >96 hours post-exposure:

• Acyclovir 20 mg/kg (maximum 800 mg) four times daily for 5-7 days, initiated 7-10 days after exposure 6, 4

Vaccination

• Post-exposure vaccination within 3-5 days may modify disease if infection has not yet occurred 4
• Vaccination is contraindicated during active infection but should be considered after recovery for susceptible individuals 6

Supportive Care

Symptomatic Management

• Adequate hydration is essential to prevent renal complications with acyclovir 2
• Antipyretics: Use acetaminophen; avoid ibuprofen due to association with severe secondary bacterial infections including necrotizing fasciitis 7
• Antipruritic measures for itching control 5

Antibiotic Therapy

Consider antibiotics only for secondary bacterial skin infections:

• Co-amoxiclav or ceftriaxone for suspected Group A streptococcal superinfection 8, 7

Infection Control

Isolate patients until all lesions have crusted over (typically 5-7 days after rash onset) 1

Healthcare Personnel Management

• Unvaccinated HCP without immunity: Furlough from days 10-21 after exposure 1, 4
• HCP with 1 dose of vaccine: Administer second dose within 3-5 days of exposure 4
• HCP with 2 doses: Monitor daily for fever and rash on days 8-21 post-exposure 4

Special Populations

Pregnancy

• Acyclovir is FDA Pregnancy Category B with no increased birth defects documented in 596 first-trimester exposures 6
• VZIG is strongly preferred for exposed pregnant women 6

Immunocompromised Patients

• Always treat with antiviral therapy regardless of timing due to risk of disseminated infection 6, 3
• Intravenous acyclovir is mandatory for severe disease 1, 3
• Household contacts should be vaccinated if seronegative and not immunocompromised 1

Common Pitfalls to Avoid

• Do not delay treatment beyond 24 hours of rash onset in candidates for antiviral therapy—efficacy diminishes significantly 2, 5
• Do not use ibuprofen for fever control due to association with severe bacterial complications 7
• Do not confuse chickenpox management with herpes zoster, which has a 72-hour (not 24-hour) treatment window 6
• Do not withhold acyclovir from immunocompromised patients even if presenting late 6
• Do not assume birth before 1980 indicates immunity in healthcare personnel—this criterion does not apply to HCP due to nosocomial transmission risk 4

Expected Outcomes with Treatment

When acyclovir is initiated within 24 hours:

• Fewer total lesions (294 vs 347 with placebo) 5
• >95% cease forming new lesions by day 3 (vs 20% still forming lesions on day 6 with placebo) 5
• Fever and constitutional symptoms limited to 3-4 days (vs >4 days in 20% of untreated patients) 5
• Accelerated progression to crusting and healing 5