Health Information and Self Care Advice for Scotland

Chickenpox

Introduction

Chickenpox is caused by a virus called the Herpes Zoster virus. It is also called the varicella-zoster virus (varicella is the medical name for chickenpox).

Chickenpox is a mild disease that most children catch at some point. It is most common in the winter and spring and usually affects lots of children at the same time, around once every three years. This is called an epidemic.

Chickenpox is most common between the ages of two and eight. You are infectious from about two days before the rash appears until roughly five days after. It takes 10-21 days for the symptoms to show after you have come into contact with the virus. This is called the 'incubation period'.

Chickenpox spreads in tiny droplets of saliva and nasal mucus coughed out by an infected person. The virus is already in these droplets before any rash appears, which is why it spreads so fast.

The chickenpox rash is made up of lots of blisters, which burst and then scab over. The Health Protection Agency recommends that children can return to school or nursery once the blisters have fully crusted over, this usually happens 5-7 days after the first scab appears. After the last scab has burst and crusted, children are no longer considered infectious.

Children who have recently been exposed to the chickenpox virus may not be able to visit friends or relatives in hospital you should telephone the ward to check first.

Shingles

After a chickenpox infection, the herpes zoster virus stays in the bodys nerve tissues (remains dormant). It does not do any harm because it is kept under control by the immune system; the part of the body that fights infection. At any time later in life, but usually when youre an adult, the virus can be reactivated (come back), causing shingles.

The causes of this are unknown, but it is usually associated with conditions that weaken the immune system such as having treatment for cancer, and HIV and also being older. About one in 10 adults who have had chickenpox experience shingles.

The first sign of shingles is usually a pain in the area of the affected nerve. Seven days later a rash will usually appear, followed by blisters, that tend to only affect one side of the body. People with shingles are contagious to those people who have not had chickenpox. However, it is not possible to catch shingles from a person who has chickenpox.

Pregnancy

If a woman comes into contact with chickenpox or shingles when pregnant, there is no problem if she has had it before, because it makes the body immune to it (re-infection is rare). This means the baby is not at risk of chickenpox even if the mother develops shingles during pregnancy.

If the woman has not had chickenpox before, or is unsure if she has, she should see her GP to be tested for it. If this shows she has not had chickenpox and has no antibodies, then chickenpox antibodies can be given. This is best given within 4 days (but can be given up to 10 days) of coming into contact with the chickenpox virus.

Chickenpox and flying

If your child has chickenpox, they may not be allowed to fly during the infectious stage (two days before the rash appears until roughly five days after). This is because the air conditioning systems in aeroplane cabins allow germs to circulate easily, and the chickenpox infection can be very dangerous for people with AIDS, a lowered immune system, and pregnant women.

Your child should be safe to fly once they are past the infectious stage and the blisters have crusted over, but it is best to check your airline policy first.
You should inform the airline as soon as you have sought medical advice and had the illness diagnosed. It is also important to let your insurer know, to make sure that you will be covered if you have to delay or cancel your holiday, or if you need to extend your stay until your child is well enough to fly home. 

Last updated on 27 June 2007 04:48 PM