Anti Viral therapy in Varicella infections

For healthy children ≤12 years, varicella is typically self-limited and antiviral therapy is not required.

Oral Antiviral Therapy (Acyclovir or Valacyclovir)is suggested for 5-7 days duration in following scenarios as a pre-emptive measure to prevent complications-

• Immunocompetent and previously unvaccinated children >12 yrs age and adolescents, as they are at increased risk of developing complications from varicella
• Individuals with chronic cutaneous or pulmonary disorders, 
• Those on long term salicylates or inhaled steroids.
• Pregnant women who develop uncomplicated varicella. 

Intravenous Acyclovir should be initiated and is given for a longer duration i.e. 7-10 days for individuals who present at any Age with complications (eg pneumonitis, encephalitis) related to varicella or are immunocompromised (HIV or any other Accquired or congenital Immunodeficiency, on Immunosuppressive medications, taking systemic steroids for > 2 weeks, etc)

Acyclovir  use does not affect incidence of Pruritus, complications or Secondary transmission in children with varicella.

ACYCLOVIR DOSING

Oral dose

• For less than 1 yr age – 10mg/kg/dose 8 hrly
• For older children- 20 mg/kg /dose 6 hrly (max 4g/day)
• For Adults 800 mg 5 times daily

IV Dose

• In infants- 500mg/m² /dose as infusion 
• In older children- 10 mg/kg/dose as infusion every 8 hrly.