This factsheet is for people who have chickenpox, parents of children with chickenpox and for people who would like information about it.
Chickenpox is a common illness that gives you a rash and can make you feel generally unwell. Anyone can catch chickenpox but it mainly affects children under ten. Most people will have chickenpox by the age of 15. It's common at all times of the year, but especially in winter and early spring.
Chickenpox is an infection caused by the varicella-zoster virus, which is part of the herpes group of viruses.
Once your chickenpox symptoms have cleared up, the virus stays dormant in your body. At any time later in life, but usually in adulthood, the virus can re-activate, causing shingles.
You will start to get symptoms around 10 to 21 days after you catch the virus.
The first symptoms of chickenpox can include:
- Sore throat
- A general feeling of being unwell
You may have these symptoms for up to six days before you get any spots. Chickenpox spots are usually very itchy. They vary in size and appear in clusters on your skin, forming a rash. You will usually get them on your face and scalp first, and then on your chest, arms and legs. You can also get spots inside your mouth and nose.
The spots are fluid-filled blisters surrounded by reddened skin. They may develop into pustules (containing pus). The blister or pustules then crust over to form scabs. The spots usually take around 16 days to heal completely.
Chickenpox is usually worse in adults than children. Adults are more likely to have complications as a result of chickenpox and are more likely to be left with rounded, hollowed-out scars on the skin, known as "pockmarks".
In otherwise healthy children, chickenpox is usually a mild infection and serious problems are rare. The most common problem linked with chickenpox in children is a bacterial infection in the spots. This causes the surrounding skin to become more red and sore. Your child's GP may prescribe antibiotics to treat the infection. Rarely, chickenpox can cause encephalitis (Inflammation of the brain) or pneumonia (an infection of the lungs).
Complications are more common in adults. The most common problem linked with chickenpox in adults is pneumonia. Another complication is liver inflammation (hepatitis).
Up to eight days after the chickenpox rash develops, some children and adults may become clumsy and unable to walk properly. This is called ataxia. It's caused by inflammation in a part of the brain called the cerebellum. This usually settles down on its own but occasionally other parts of the brain become affected and can cause longer-term problems.
Chickenpox is caused by the varicella-zoster virus and is very contagious. If you haven't had chickenpox before and someone in your house has it, you have very high chance of catching it.
The virus causing chickenpox is usually transferred from person to person through the air by coughing and sneezing. It can also be passed on from person to person by direct contact with the fluid from broken chickenpox blisters, either from the person who is infected or by other items, such as clothing, that have been in contact with broken blisters. It's also possible to get chickenpox from someone who has shingles through contact with fluid from the shingles rash.
People who have been infected with chickenpox can pass the virus on about two to four days before the rash breaks out. You remain infections until five or six days after the rash first appears. Children should be kept home from school or nursery during this time.
Once you've had chickenpox you will usually be immune and won't catch it again. However, on rare occasions people can get it again.
Most people with chickenpox get better without treatment. However, over-the-counter treatments are available to help relieve your symptoms.
It can be difficult to resist, but try not to scratch your spots as this can lead to scarring. You can help relieve the itchiness by keeping your skin cool - wear light clothing and bathe or sponge your skin with tepid water. This will also help to reduce a high temperature.
You may find crotamition cream or lotion (eg Eurax) helps to soothe itching. You can buy this from your pharmacist. Calamine lotion, which is the traditional alternative, isn't as effective.
Some people take antihistamine tablets to help reduce the itchiness, but there is little evidence to suggest that this helps. Some antihistamines can make you very drowsy, so can help you sleep and therefore stop you scratching at night.
Paracetamol or ibruprofen may ease your discomfort if your skin is painful, and will help lower a fever and relieve a sore throat.
Always follow the instructions in the patient information that comes with the medicine and ask your pharmacist for advice on whether it's suitable for your child's individual circumstances.
To prevent further spread, children who have chickenpox should be kept off school for five days from when the rash first appears.
If you have chickenpox, you should stay away from public areas to avoid contact with people who haven't had it, especially newborn babies, pregnant women and people with a weakened immune system.
There is a vaccine for chickenpox but currently it's only given to certain people, such as pregnant women and healthcare workers who have direct contact with patients. This includes caterers, cleaners and GP receptionists as well as nurses, doctors and other health professionals. This protects patients from catching chickenpox from an infected carer.
If you are pregnant
Most women of child bearing age will have had chickenpox and will be immune. However, if you haven't had chickenpox before and catch it when you are pregnant it can make you feel very unwell and some women can develop pneumonia.
Depending on how many weeks pregnant you are, chickenpox may affect your unborn baby.
Chickenpox in the first half of pregnancy
If you catch chickenpox in the first 20 weeks of pregnancy, it may, in rare cases, affect your unborn baby. It can affect development of the arms, legs, brains or eyes, cause scarring on the baby's skin and poor growth. This is called fetal varicella syndrome.
Chickenpox in the second half of pregnancy
If you get chickenpox after 28 weeks of pregnancy there doesn't seem to be any risk of it causing your baby to develop an abnormality. However, your baby may catch it from you and develop a type of chickenpox called symptomatic varicella infection. This means your baby may be ill when he or she is born. The baby's infection may be worse if you get chickenpox four days before delivery and up to two days after.
Contact your GP as soon as possible if you think you have chickenpox when you are pregnant or within seven days after giving birth.
Treatment for pregnant women
If you are more than 20 weeks pregnant and get chickenpox, your doctor may prescribe an antiviral medicine called aciclovir. Although it doesn't cure the illness, it makes it less severe. You need to start taking this medicine within 24 hours of the rash appearing. Aciclovir is sometimes also prescribed for newborn babies.
If you aren't immune to chickenpox and have been in contact with someone who has it, go and see your GP immediately - you can have an injection called varicella zoster immunoglobulin (VZIG) which contains antibodies against the virus. This will prevent you getting chickenpox, but you need to have it within 10 days of exposure to the virus.
If you have a weakened immune system
You are more at risk of severe complications from chickenpox if you have a weakened immune system, for example if you are having treatment for cancer, you have HIV/AIDS or you are over 65. You should contact your GP as soon as possible after contact with someone who has chickenpox if you haven't had it before. Your GP can then prescribe the appropriate antiviral treatment.
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