When it affects children, chickenpox is usually a fairly mild illness producing a temperature, cough and an itchy rash. Most children miss a week or so of school and quickly return to normal good health.
But when adults catch chickenpox it can be a far more serious problem.
Chickenpox is caused by one of the herpes family of viruses — varicella-zoster. It spreads rapidly via airborne droplets from coughing or sneezing, direct contact with the rash, or contact with sheets or clothes recently used by an infected person. Chickenpox is easily caught. An infection normally gives life-long immunity to further attacks.
Fortunately, this means most adults are immune to the illness. But for those who didn't catch it in childhood, an attack of chickenpox can produce serious, sometimes lethal, complications. Adults are at risk of pneumonia and, less commonly, encephalitis (infection of the brain).
Particularly at risk are smokers, those with lung disease and pregnant women. Infection in pregnancy can affect the baby and produce severe abnormalities.
For these reasons, adults who are unsure if they had chickenpox as a child should consider being tested to see if they are immune to the disease. This is particularly important if they are likely to be in contact with children, the main source of infections.
Adults who are not immune can be vaccinated against varicella-zoster so that they are protected if they do come into contact with chickenpox sufferers.
In certain cases, an injection of a medication called Zoster Immunoglobulin may be given to non-immune people following contact with chickenpox sufferers. This medication contains antibodies to the varicella-zoster virus, and can prevent or modify an attack of chickenpox when given within 96 hours of exposure, reducing the risk of serious complications.
Last Reviewed: 23 November 2009