Acute Varicella Zoster (Chickenpox)

Chickenpox is a highly contagious viral infection causing an itchy rash and fever. It is most common in children but can affect anyone who is not immune.

Overview

Acute varicella zoster, commonly known as chickenpox, is a highly contagious disease caused by the varicella-zoster virus (VZV). It is characterized by an itchy, blister-like rash that typically appears on the face, scalp, and trunk before spreading to other parts of the body.

Chickenpox is usually a mild illness in healthy children, but it can cause serious complications in adults, newborns, pregnant women, and immunocompromised individuals. Vaccination has significantly reduced the incidence of chickenpox.

Symptoms

  • Rash: Red, itchy rash that progresses from spots to fluid-filled blisters, then crusts over in 5-7 days.
  • Fever: Mild to moderate fever (often 100-102°F).
  • Fatigue and malaise: Generalized feeling of being unwell.
  • Loss of appetite: Reduced desire to eat.
  • Headache: Mild headache may occur.
  • New spots: New crops of blisters appear over several days.
  • Complications: In severe cases, pneumonia, encephalitis, or secondary bacterial infections.

Causes

  • Varicella-zoster virus (VZV): The virus causes both chickenpox (primary infection) and shingles (reactivation).
  • Transmission: Spread through respiratory droplets (coughing, sneezing) or direct contact with fluid from chickenpox blisters.
  • Incubation period: Symptoms typically appear 10-21 days after exposure.
  • Contagious period: Contagious from 1-2 days before the rash appears until all blisters have crusted over.

Treatment

  • Rest and hydration: Adequate rest and fluid intake to prevent dehydration.
  • Itch relief: Calamine lotion, antihistamines, and oatmeal baths to relieve itching.
  • Fever management: Acetaminophen (avoid aspirin in children due to Reye's syndrome risk).
  • Antiviral medications: Acyclovir or similar drugs for severe cases, adults, or high-risk individuals.
  • Prevention of scratching: Keep fingernails short and use mittens for small children.
  • Vaccination: The varicella vaccine provides effective prevention.