What is chickenpox?
Chickenpox is a very contagious but benign childhood illness, accompanied by blisters on the skin and itch. Almost all children go through this illness.
What causes it?
Chickenpox is caused by the varicella-zoster virus. The virus is spread through the air (by coughed-out droplets) or by direct contact with the blisters. The incubation period (the time between infection and the first blisters) is two to three weeks. The child remains contagious until all the blisters have dried up, a period of about 10 to 12 days. The varicella-zoster virus is the same virus that causes shingles (herpes zoster).
What does it look like?
The first signs are red spots that quickly develop into blisters filled with clear fluid. After a few days the blisters dry up and form crusts, which disappear by themselves but sometimes leave a small scar. The blisters can occur anywhere on the skin; characteristically, blisters can also develop on the scalp. Another common feature is itch. A sore throat can develop and sometimes mild fever, though children are usually not really ill. Sometimes bacteria can settle in the remains of the blisters, especially after scratching, which can cause larger local infections and often larger scars.
Who gets it?
It is mainly children between 2 and 8 years old who go through chickenpox. Once a child has had it, antibodies against the virus have been formed, so in principle the illness cannot strike again on re-exposure. This can, however, happen in people with strongly reduced immunity, in whom a chickenpox infection can even lead to dangerous situations. During the infection, avoid contact with babies, people with a weakened immune system and pregnant women.
How is it treated?
Chickenpox settles on its own, so treatment is not needed. Sometimes the itch is so severe that treatment with a zinc lotion is useful. If there is a bacterial infection of the blisters, a disinfectant cream or antibiotic cream can be applied. When severe symptoms and/or high fever occur, the immune system may not be working adequately or a complication may have arisen; it is then important to consult a doctor quickly. Make a note somewhere that your child has had chickenpox and keep this information safe, as it may be important later to know for certain whether they actually had the infection.
For whom can chickenpox be dangerous?
Adults (and children older than 14) who get chickenpox are usually much more ill than young children. Pregnant women and people with reduced immunity in particular can also develop more serious complications such as encephalitis and pneumonia. Babies too (especially of mothers who have not had chickenpox themselves and so provide no antibody protection) are at risk of a more severe course. In these groups, treatment with antiviral medicines is usually warranted. Because this treatment must be started quickly to be optimally effective, it is wise to contact a doctor promptly.
When to see a doctor
See a doctor promptly if an adult, a baby, a pregnant woman or someone with reduced immunity gets chickenpox, or if there is high fever, severe illness or signs of a complication.