What is the recommended assessment and management approach for patients with chicken pox (varicella)?

Chicken Pox Assessment, Workup, and Management

Acyclovir should be administered within 24 hours of rash onset for high-risk patients with chicken pox (varicella), while otherwise healthy children generally do not require antiviral therapy. 1

Clinical Assessment

Diagnosis

• Characteristic vesicular rash: pruritic lesions in various stages (macules, papules, vesicles, and crusts)
• Distribution: begins on face and trunk, spreads centrifugally to extremities
• Systemic symptoms: fever, malaise, headache, anorexia

High-Risk Populations

• Persons aged >12 years
• Pregnant women
• Immunocompromised individuals
• Persons with chronic cutaneous or pulmonary disorders
• Persons receiving long-term salicylate therapy
• Persons receiving corticosteroids (≥20 mg/day of prednisone or equivalent)
• Neonates whose mothers developed varicella 5 days before to 2 days after delivery

Management Approach

Antiviral Therapy

Indications for Oral Acyclovir:

• High-risk immunocompetent patients if started within 24 hours of rash onset
• Secondary household contacts at increased risk for moderate to severe disease
• Adults and adolescents (reduces duration and severity of illness)

Dosing for Oral Acyclovir:

• Children (2 years and older): 20 mg/kg per dose 4 times daily (80 mg/kg/day) for 5 days (maximum 800 mg per dose) 2
• Adults and children >40 kg: 800 mg 4 times daily for 5 days 2

Indications for Intravenous Acyclovir:

• Immunocompromised patients
• Pregnant women with complications (e.g., pneumonia)
• Patients with severe disease or complications
• Neonates with varicella

Dosing for IV Acyclovir:

• 10 mg/kg or 500 mg/m² every 8 hours 3
• Ensure adequate hydration and monitor renal function 3

Dose Adjustment for Renal Impairment

• Modify dosage based on creatinine clearance as per FDA guidelines 2
• For hemodialysis patients, administer an additional dose after each dialysis session 2

Isolation and Infection Control

Contact Precautions

• Isolate patient until all lesions are dry and crusted 4
• For hospitalized patients:
  • Single room or maintain >3 ft spatial separation
  • Use appropriate PPE
  • Limit patient transport and movement
  • Use dedicated patient-care equipment 4

Airborne Precautions

• Implement for patients with disseminated disease or immunocompromised patients
• Place in airborne isolation room with negative pressure when possible
• If negative air-flow rooms unavailable, isolate in closed rooms 4

Post-Exposure Prophylaxis

Varicella Zoster Immune Globulin (VZIG)

• Indicated for exposed high-risk individuals without immunity:

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

• Dosage: 125 units/10 kg body weight (minimum 125 units, maximum 625 units) 1

• Administer within 96 hours of exposure for maximum effectiveness

Post-Exposure Vaccination

• May be effective if given within 3-5 days of exposure
• Consider for exposed healthcare workers without immunity 4

Special Considerations

Pregnant Women

• At higher risk for severe disease and complications
• VZIG recommended for susceptible pregnant women after exposure
• Primary goal is to prevent complications in the mother rather than protect the fetus
• Intravenous acyclovir recommended for serious complications (e.g., pneumonia) 1

Immunocompromised Patients

• Require aggressive management with IV acyclovir
• Consider sequential therapy (IV followed by oral) once clinically improving 5
• Monitor closely for dissemination and visceral complications

Healthcare Personnel

• Only staff with documented immunity should care for patients with varicella
• Evidence of immunity includes: 2 doses of varicella vaccine, laboratory evidence of immunity, or verified history of varicella/herpes zoster 4
• Non-immune exposed healthcare workers should be excluded from duty from day 8 after first exposure through day 21 after last exposure 4

Common Pitfalls to Avoid

• Delaying antiviral therapy beyond 24 hours of rash onset significantly reduces effectiveness
• Failing to recognize high-risk patients who require antiviral therapy
• Inadequate isolation precautions leading to nosocomial spread
• Underestimating the severity of varicella in adults, pregnant women, and immunocompromised patients
• Using insufficient dosing of acyclovir (varicella requires higher doses than herpes simplex infections)

By following this structured approach to assessment and management, clinicians can effectively treat chicken pox while minimizing complications and preventing transmission to other susceptible individuals.