What is the recommended management for a patient with chicken pox, including treatment options for fever, itching, and high-risk complications?

Management of Chickenpox

Antiviral Treatment Indications

Acyclovir should be initiated in all patients at increased risk for complications, including those over 12 years of age, immunocompromised individuals, patients with chronic cutaneous or pulmonary disorders, and those receiving long-term salicylate or corticosteroid therapy. 1

High-Risk Populations Requiring Treatment:

• Adolescents and adults (>12 years): Higher complication rates warrant antiviral therapy 1
• Immunocompromised patients: Require aggressive treatment, preferably intravenous acyclovir 1, 2
• Chronic disease patients: Those with cutaneous or pulmonary disorders should receive acyclovir 1
• Patients on chronic medications: Long-term salicylate or corticosteroid therapy increases risk 1
• Neonates: Require careful evaluation and often intravenous therapy 1

Timing of Treatment:

Treatment is most effective when initiated within 24 hours of rash onset, though benefit may still occur if started later 3, 4. Therapy should begin at the earliest sign or symptom of chickenpox 3.

Antiviral Dosing Regimens

Oral Acyclovir (FDA-Approved Dosing):

Children (2 years and older, <40 kg):

• 20 mg/kg per dose orally 4 times daily for 5 days (maximum 800 mg/day) 3

Adults and children >40 kg:

• 800 mg orally 4 times daily for 5 days 3

Alternative high-dose regimen for severe cases:

• 800 mg orally 5 times daily for 7-10 days 2

Intravenous Acyclovir:

• 10 mg/kg IV every 8 hours for severe disease or immunocompromised patients 1, 2
• Indicated for immunocompromised children and adults with complications 3, 2
• Requires adequate hydration and monitoring of renal function and mental status 2

Valacyclovir (Alternative):

Pediatric patients (2 to <18 years):

• 20 mg/kg administered 3 times daily for 5 days (maximum 1 gram per dose) 5

Symptomatic Management

Fever Control:

Use acetaminophen (paracetamol) exclusively for fever management in chickenpox patients. 6

• Avoid NSAIDs (ibuprofen, aspirin): Associated with increased risk of severe bacterial skin infections 6
• Avoid aspirin specifically: Risk of Reye's syndrome in children with varicella 1

Pruritus (Itching) Management:

• Antihistamines for symptomatic relief 7, 8
• Cool compresses to affected areas 8
• Calamine lotion for topical relief 8
• Keep fingernails short to prevent secondary bacterial infection from scratching 8

Post-Exposure Prophylaxis

Varicella-Zoster Immune Globulin (VZIG):

VZIG must be administered within 96 hours (ideally within 10 days) of exposure to high-risk susceptible individuals. 9, 1

High-risk populations requiring VZIG:

• Immunocompromised patients 9, 1
• Pregnant women without immunity 9, 1
• Neonates with maternal exposure 1

Important caveat: VZIG may prolong the incubation period to 28 days, requiring extended monitoring 1

Alternative Prophylaxis:

If VZIG is unavailable, acyclovir 20 mg/kg (maximum 800 mg) four times daily for 5-7 days, initiated 7-10 days after exposure 1

Post-Exposure Vaccination:

Vaccination within 3-5 days of exposure may modify disease if infection has not yet occurred 1

Special Populations

Immunocompromised Patients:

• Discontinue immunomodulator therapy if possible during active infection 9, 1
• Initiate intravenous acyclovir immediately at 10 mg/kg every 8 hours 1, 2
• Require intensive monitoring and tertiary-level supportive care 9
• Higher mortality risk, particularly with cell-mediated immune deficits 9

Pregnant Women:

• VZIG is first-line prophylaxis if exposed 9, 1
• Treatment decisions require careful risk-benefit discussion 9
• Fetal vaccinia is rare but serious; vaccination during pregnancy should not ordinarily prompt termination 9

Patients on Immunomodulators:

• Do not initiate immunomodulators during active chickenpox 9
• Consider temporary discontinuation in severe cases 9, 1

Renal Impairment Dosing Adjustments

For creatinine clearance 10-25 mL/min:

• 800 mg every 8 hours 3

For creatinine clearance 0-10 mL/min:

• 800 mg every 12 hours 3

Hemodialysis patients:

• Administer additional dose after each dialysis session 3

Infection Control Measures

Isolate patients until all lesions have completely crusted over (typically 5-7 days after rash onset). 1, 10

Transmission Prevention:

• Active transmission period: 1-2 days before rash onset until all lesions crust 10
• Use separate towels and pillows 10
• Maintain meticulous hand hygiene 10
• Avoid swimming pools, gyms, and contact sports until lesions completely crusted 10

Healthcare Worker Management:

• Unvaccinated healthcare personnel without immunity should be furloughed days 10-21 after exposure 1
• Those with one vaccine dose should receive second dose within 3-5 days of exposure 1
• Monitor vaccinated personnel daily for fever and rash days 8-21 post-exposure 1

Vaccination Considerations

Varicella vaccine should not be administered to immunocompromised patients due to risk of disseminated viral infection. 9, 1

• Household contacts of immunocompromised individuals should be vaccinated if seronegative 1
• VZV-naive patients on methotrexate should strongly consider vaccination before immunosuppression 9
• Complete vaccination course at least 3 weeks before starting immunomodulators 9

Common Pitfalls to Avoid

1. Do not use NSAIDs for fever control: Increased risk of severe bacterial skin infections 6
2. Do not delay antiviral therapy: Most effective within 24 hours of rash onset 3, 4
3. Do not forget renal dose adjustments: Acyclovir requires modification in renal impairment 3
4. Do not miss VZIG window: Must be given within 96 hours of exposure 1
5. Do not vaccinate immunocompromised patients: Risk of disseminated disease 9, 1