What is the treatment for chickenpox (varicella)?

Treatment of Chickenpox (Varicella)

For otherwise healthy children and adults with uncomplicated chickenpox, supportive care is the primary treatment, while oral acyclovir is specifically indicated for adolescents ≥13 years, immunocompromised patients, those with chronic pulmonary or cutaneous disorders, and patients on long-term salicylate or corticosteroid therapy. 1, 2

Supportive Care (Primary Treatment for Healthy Patients)

• Symptomatic management includes lukewarm baths with colloidal oatmeal to relieve itching 3
• Maintain adequate hydration throughout the illness 2
• Isolation is required until all lesions have crusted over (typically 5-7 days) to prevent transmission 3, 1
• Avoid salicylates (aspirin) for 6 weeks after varicella due to Reye syndrome risk 4

Antiviral Therapy with Acyclovir

Clear Indications for Acyclovir Treatment

The American Academy of Pediatrics establishes specific high-risk groups requiring acyclovir:

• All adolescents and adults ≥13 years of age 1
• Immunocompromised patients (require IV acyclovir) 1
• Children with chronic cutaneous or pulmonary disorders 1
• Patients on long-term salicylate therapy 1
• Patients receiving corticosteroid therapy 1

Dosing Regimens

Oral Acyclovir (for immunocompetent patients meeting above criteria):

• Children <40 kg: 20 mg/kg per dose (maximum 800 mg) orally 4 times daily for 5 days 1, 2
• Adults and children >40 kg: 800 mg orally 4 times daily for 5 days 1, 2
• Treatment must be initiated within 24 hours of rash onset for optimal efficacy 2, 5

Intravenous Acyclovir (for severe disease or immunocompromised patients):

• 10 mg/kg every 8 hours for 7-10 days 1
• This is the standard for immunocompromised children and those with visceral dissemination 6, 7

Renal Dosing Adjustments

For patients with renal impairment, acyclovir dosing must be modified 2:

• 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 2

Post-Exposure Prophylaxis

For Immunocompetent Exposed Individuals

• Varicella vaccine administered within 3 days of exposure is >90% effective in preventing disease 4
• Vaccine given within 5 days is 70% effective in preventing disease and 100% effective in modifying severe disease 4
• Susceptible household contacts of immunocompromised patients should be vaccinated to prevent transmission 1

For High-Risk Exposed Individuals Without Immunity

Varicella-zoster immune globulin (VZIG) is indicated for:

• Immunocompromised patients without immunity (administer as soon as possible, up to 10 days after exposure) 1
• Pregnant women without evidence of immunity 1
• Neonates born to mothers with varicella 5 days before to 2 days after delivery 1
• Premature infants <28 weeks gestation or <1,000 g regardless of maternal immunity 1

If VZIG is unavailable:

• Oral acyclovir 10 mg/kg four times daily for 7 days, starting 7-10 days after exposure 1

Special Populations

Infants and Young Children

• For otherwise healthy infants (e.g., 8-month-old), supportive care alone is recommended 3
• Antiviral therapy is not routinely indicated unless the infant is immunocompromised or receiving immunosuppressive therapy 3
• Most cases resolve without complications within 5-7 days 3

Immunocompromised Patients

• Sequential therapy approach: Start with IV acyclovir for minimum 48 hours, then switch to oral if patient is afebrile, has no new lesions for 24 hours, and has no internal organ involvement 7
• This approach reduces hospitalization duration while maintaining safety 7
• Live varicella vaccine is contraindicated in immunocompromised patients due to risk of disseminated infection 1

Healthcare Workers

• Unvaccinated healthcare workers exposed to VZV should be furloughed days 10-21 after exposure 1
• Healthcare workers who develop vaccine-related rash should avoid contact with high-risk patients until all lesions resolve 8

Critical Pitfalls to Avoid

• Do not initiate acyclovir therapy >24 hours after rash onset in immunocompetent patients, as efficacy is significantly reduced 2, 5
• Do not rely on antibody titers in patients with nephrotic-range proteinuria or receiving IVIG, as they are unreliable 1
• Do not administer live varicella vaccine during or within 3 months of stopping immunosuppressive therapy 8
• Do not use aspirin or salicylates during acute chickenpox or for 6 weeks after varicella vaccination 4

Evidence Quality Note

The treatment recommendations are based on high-quality FDA-approved labeling 2, recent guidelines from the American Academy of Pediatrics and CDC 3, 1, and landmark randomized controlled trials demonstrating that acyclovir reduces duration of fever, constitutional symptoms, and time to cutaneous healing when initiated within 24 hours of rash onset 5. The evidence consistently shows that while acyclovir reduces disease severity and duration, it has not been proven to reduce rare serious complications in otherwise healthy children 5.