Cause by varicella – zoster virus (human herpes virus 3)
Mode of transmission is by droplet infection from the upper respiratory tract or from the discharged by ruptured lesions on the skin.
The disease is contagious till pustules disappear.

Clinical Features

Prodromal Phase – low grade fever, malaise, headache and anorexia.

Rash on the Trunk
  • First appears on the trunk and then face and finally on the limbs. The lesions are maximum on the trunk and minimum on the limbs.
  • Appears as macules and then progress to papules, vesicles and pustules. The lesions finally dry up to form scales.
  • These lesions are very itchy
  • New lesions occur in every 2 – 4 days, each crop associated with fever.


  • Myocarditis
  • Hepatitis
  • Meningitis
  • Acute glomerulonephritis
  • Secondary bacterial infection
  • Cerebellar ataxia
  • Pneumonitis
  • Arthritis
  • Congenital varicella


  • Mainly clinical.
  • A Tzanck smear of vesicular fluid demonstrates multinucleated giant cells and epithelial cells with eosinophilic intranuclear inclusion bodies.
  • Isolated the virus – culture
  • Direct immunofluorescence test
  • PCR – identify viral gene


  • No treatment required in majority of cases.
  • Symptomatic treatment – antihistaminic and calamine lotion.
  • Acyclovir (15 mg/kg 5 times a day for 7 days) – for adults and immunocompromised patients. It reduces the complications of chickenpox if given within 24 hours.
  • Secondary bacterial infection is treated with local antiseptic or systemic antibiotics like cloxacillin.


  • Live Attenuated Vaccine is given to prevent chickenpox in immunocompromised children and adult who are at high risk of infections. It should not be given to pregnant and immunocompromised patients.
  • Passive Prophylaxis for immunocompromised patient or pregnant women with history of significant exposure within last 96 hours.