Childhood Diseases

Updated 09 April 2018

Risk factors for chickenpox

The highest risk for contracting chickenpox is associated with living in the same household as a person with the disease.


Close exposure or contact with someone with early chickenpox will put you at risk of infection. Even spending some time in the same room as a person with early chicken pox will put you at risk.

The highest risk is associated with living in the same household as a person with chickenpox. Nine out of 10 people who haven’t had chickenpox before will contract the disease under these circumstances.

Generally, children are least likely to have complications from chickenpox. Babies under one year old are more vulnerable and, from puberty onwards, teenagers and adults are more prone to severe chickenpox and its complications.

Certain groups of people are particularly at risk for severe chickenpox. Children and adults whose immune systems are compromised are at particular risk.

Examples of conditions that compromise the immune system include various forms of cancer, leukaemia, lymphoma and HIV/AIDS.

Some drugs, such as high doses of cortisone used for severe asthma, arthritis and kidney disease, may also compromise the immune system.

Immune-compromised people are prone to: 

An extensive and severe rash.
Possible damage to internal organs, including the liver and lungs. 
Haemorrhagic chickenpox (which involves severe bleeding).
A prolonged course of the illness.

Chickenpox may even be fatal in immune-compromised people.

Reviewed by paediatrician Prof Eugene Weinberg. MBChB; FCP (SA); PAED (SA). March 2018.