Australian experts have warned that, although chickenpox is a common and usually mild viral illness, serious complications sometimes occur. These include encephalitis (infection of the brain) and pneumonia. Tragically, in rare cases these complications are fatal. Particularly at risk are those with other medical problems which may lower their ability to resist infection.

Adults who develop chickenpox are generally unwell with a flu-like illness and may have more serious complications such as pneumonia.

Epidemics of chickenpox usually occur every 4 or 5 years and are most common in springtime. Even in those children who have a straightforward attack, chickenpox means at least a week away from school, which may interfere with crucial examinations. Parents may need to stay home from work to look after their children. Because chickenpox is highly contagious, non-immune brothers and sisters of affected children will invariably catch the infection, resulting in further disruption to the family.

Symptoms of chickenpox
Affected people usually have a fever, cough and a very uncomfortable itchy rash. Secondary skin infection in the spots of chickenpox can result in permanent scarring. Girls who don't catch the infection in childhood run the risk of catching it later in life, when they might be pregnant. Infection in pregnancy has serious risks for the baby.

Preventing chickenpox
Chickenpox can now be prevented by vaccination. A single injection at 18 months of age is now recommended by the National Health and Medical Research Council to protect children against the disease. There is a catch-up dose for adolescents at 10 to 13 years of age for those who have not been vaccinated, or who have not had chickenpox. Although there may be a cost associated with vaccinating children against chickenpox, for many parents it will be money well spent.

Chickenpox in adults
One of the later complications of chickenpox is shingles, a painful rash that affects adults when the chickenpox virus is reactivated later in life. Researchers are optimistic that chickenpox vaccination may reduce the occurrence and severity of shingles.