Education Materials

Mount Sinai Hospital is a University of Toronto patient care, teaching, and research centre.
Mount Sinai Hospital is a University of Toronto patient care, teaching, and research centre.

Frequently Asked Questions

FAQ: Chickenpox (Varicella)

This document has been prepared for educational purposes by Maxine Armstrong RN, BASc and Karen Green, RN CIC Should you have any questions regarding individual health concerns or health care practices, please consult your physician or health care provider directly.

» What is Chickenpox?

Chickenpox is a very contagious disease caused by the varicella virus. The virus usually infects children, however adults who were not infected as children can also become infected if exposed to the virus. Chickenpox is most common in late winter to early spring.

» What are the Symptoms?

The symptoms include itchy rash, mild fever and other systemic symptoms. The rash may begin as smooth, red spots then develop into blisters by the third to fourth day. The disease is often more severe in adolescents, adults and individuals with compromised immune systems.

» How is it Transmitted?

Chickenpox is spread from person to person by direct, droplet or airbourne contact with respiratory secretions or fluid from the skin lesions of an infected individual. In utero infection can occur if a susceptible mother becomes infected with chickenpox during pregnancy.

The person with chickenpox is most contagious for 1-2 days before and shortly after the onset of rash. Chickenpox can be contagious for approximately 5 days after the onset of rash or until the chickenpox lesions are crusted. The contagious period may be prolonged in the immune compromised person.

» Who is at risk?

Anyone who has never had chickenpox is at risk of getting it if they are exposed to someone with chickenpox or shingles (a reactivation of the chickenpox virus). Most healthy children and adults will be uncomfortable for a few days but infrequently develop complications. However, immunocompromised children and adults (eg. individuals with HIV, leukemia or other conditions that affect their immune system), newborns who were exposed to chickenpox in utero, and the elderly may develop pneumonia as a complication of chickenpox.

» What are the Control Measures?

  • Where possible, protect susceptible individuals who are at high risk for complications from exposure to chickenpox.
  • Varicella vaccine is available for immunization of susceptible individuals.
  • The current varicella vaccine is not recommended for preventing the occurrence of chickenpox following exposure to the virus. However there is some evidence to support the fact that if the vaccine is given within three days of exposure, it may prevent subsequent clinical illness in the contact.
  • Varicella zoster immune globulin (VZIG) can be administered to appropriate exposed candidates within 96 hours after exposure to provide passive antibody protection following exposure.
  • Children with uncomplicated chickenpox should be excused from school or childcare until the sixth day after the onset of the rash, or sooner if the lesions are crusted.
  • Lesions can be covered
  • Older children or staff members should wash their hands if they touch potentially infectious lesions.
  • In institutions or settings where chickenpox exposures pose significant risk to susceptible individuals, the source of infection should be investigated and susceptible contacts identified for potential interventions.
  • Health care staff or people working with high risk populations should know their chickenpox immune status.

» What Treatments are Available?

Treatment of uncomplicated chickenpox in a healthy child is not recommended. Oral and intravenous antiviral therapy is available for immuno compromised individuals to help lessen the severity and complications of varicella infection.

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