What is the treatment for chicken pox (varicella)?

Treatment of Chicken Pox (Varicella)

Oral acyclovir is the primary treatment for chicken pox (varicella) in high-risk individuals, with dosing of 20 mg/kg (maximum 800 mg) 4 times daily for 5 days, ideally started within 24 hours of rash onset. 1, 2, 3

Treatment Approach Based on Patient Population

Healthy Children Under 12 Years

• Symptomatic treatment is usually adequate for otherwise healthy children under 12 years of age 1
• Supportive care includes:
  • Antipyretics for fever (avoid aspirin due to risk of Reye syndrome) 1
  • Antihistamines or topical calamine lotion for pruritus 4
  • Maintaining adequate hydration 3

High-Risk Individuals (Treatment Indicated)

• Oral acyclovir should be considered for:
  • Persons aged >12 years 1
  • Individuals with chronic cutaneous or pulmonary disorders 1
  • Persons receiving long-term salicylate therapy 1
  • Persons receiving short, intermittent, or aerosolized courses of corticosteroids 1
  • Secondary household contacts of infected children 1

Dosing Recommendations

• Children (2 years and older): 20 mg/kg per dose orally 4 times daily (80 mg/kg/day) for 5 days 3
• Children over 40 kg and adults: 800 mg 4 times daily for 5 days 3
• Treatment should be initiated within 24 hours of rash onset for maximum effectiveness 3, 5

Immunocompromised Patients

• Intravenous acyclovir is indicated for varicella-zoster infections in immunocompromised patients 3
• Recommended dosage: 10 mg/kg IV every 8 hours 2
• Duration of treatment typically 7-10 days depending on clinical response 6

Special Considerations

Pregnant Women

• Acyclovir is classified as a Category B drug in pregnancy 1
• Routine use is not recommended for pregnant women with uncomplicated varicella 1
• In cases of serious complications (e.g., pneumonia), intravenous acyclovir should be considered 1
• A registry of acyclovir use during pregnancy showed no increased risk of birth defects 3

Post-Exposure Prophylaxis

• For susceptible high-risk individuals exposed to varicella:
  • Varicella zoster immune globulin (VZIG) should be administered within 96 hours of exposure 1
  • Vaccination is the method of choice for healthy susceptible individuals after exposure 1
  • Acyclovir is not indicated for prophylactic use among otherwise healthy individuals 1

Important Clinical Pearls and Pitfalls

• Early treatment is crucial - acyclovir must be started within 24 hours of rash onset for maximum effectiveness 3, 5
• Adequate hydration should be maintained during treatment 3
• Monitor renal function in patients receiving acyclovir, especially those with pre-existing renal impairment 3
• Dosage adjustment is necessary for patients with renal impairment 3
• Avoid contact with susceptible individuals until all lesions have crusted over 1
• Vaccination is the preferred method for prevention of varicella in susceptible individuals 1

Monitoring and Follow-up

• Monitor for signs of bacterial superinfection (increasing erythema, warmth, tenderness, purulent drainage) 4
• Secondary bacterial skin infections may require antibiotic therapy 4
• Most cases resolve without complications within 1-2 weeks 1
• Patients with severe disease or complications should be hospitalized for close monitoring and intravenous therapy 7