Chickenpox is a common illness that mainly affects children and causes an itchy, spotty rash.
Most children will catch chickenpox at some point. It can also occur in adults who didn't have it when they were a child.
It's usually mild and clears up in a week or so, but it can be dangerous for some people, such as pregnant women, newborn babies and people with a weakened immune system.
This page covers:
Symptoms of chickenpox
The symptoms of chickenpox start one to three weeks after becoming infected.
The main symptom is a rash that develops in three stages:
- stage 1: spots – red raised spots develop on the face or chest before spreading to other parts of the body
- stage 2: blisters – over the next few hours or the following day, very itchy fluid-filled blisters develop on top of the spots
- stage 3: scabs and crusts – after a further few days, the blisters dry out and scab over to form a crust; the crusts then gradually fall off by themselves over the next week or two
Chickenpox is contagious until all the blisters have scabbed over, which usually happens about five or six days after the rash appeared.
Read about the symptoms of chickenpox for more information and pictures of the different stages of the rash.
How to treat chickenpox at home
Chickenpox can usually be treated at home.
You or your child will probably feel pretty miserable and uncomfortable, but treatment can help relieve the symptoms.
The following can help:
- take over-the-counter painkillers such as paracetamol to relieve fever and discomfort
- use calamine lotion, moisturising creams or cooling gels to ease itching
- tap or pat the skin rather than scratching it – it's important to avoid scratching because this can lead to further problems
- drink plenty of fluids to stay hydrated
You should also take steps to stop chickenpox spreading, such as staying away from school or work until the last blister has scabbed over.
Read more about how to treat chickenpox.
When to get medical advice
Chickenpox is normally mild and gets better on its own. But some people can become more seriously ill and need to see a doctor.
It's a good idea to contact your GP or NHS Direct Wales on 0845 46 47 for advice if:
- you're not sure if you or your child has chickenpox
- your baby is less than four weeks old and has chickenpox
- you develop chickenpox as an adult
- the symptoms haven't started to improve after six days
- you've been in contact with someone who has chickenpox (or you have symptoms) and you're pregnant, breastfeeding or have a weakened immune system
- you or your child has signs of chickenpox complications, such as swollen and painful skin, difficulty breathing or dehydration
Also consider getting advice if you're originally from a country near the equator (the tropics) and you've been in close contact with someone who has chickenpox.
Chickenpox is much more common in adults from these areas and you may need treatment to help stop you becoming seriously ill.
How you catch chickenpox
Chickenpox is caused by a virus that spreads very easily to people who haven't had it before. If you have had it before, you'll usually be immune for life.
The infection is spread in the fluid found in chickenpox blisters and the droplets in the coughs or sneezes of someone with the infection.
You can catch chickenpox from:
- contaminated surfaces
- contaminated objects, such as toys or bedding
- touching chickenpox blisters or the shingles rash
- face-to-face contact with an infected person, such as having a conversation
- being in the same room as an infected person for 15 minutes or more
Someone with chickenpox is infectious from one or two days before the rash appears until all the blisters have dried out and crusted over.
Most people with chickenpox will make a full recovery. But occasionally serious complications can occur.
These are more common in adults, pregnant women, newborn babies and people with weakened immune systems.
Possible complications include:
- a bacterial skin infection – this can cause the skin to become red, swollen and painful
- a lung infection (pneumonia) – this can cause a persistent cough, breathing difficulties and chest pain
- pregnancy problems – including the infection spreading to the unborn baby
Some people with chickenpox may develop shingles later in life. This is a painful, blistery rash caused by the chickenpox virus becoming reactivated.
Read more about the complications of chickenpox.
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The main symptom of chickenpox is a red rash made up of spots or blisters.
It usually takes between one and three weeks for symptoms to appear after becoming infected (the incubation period).
Sometimes other symptoms may start a day or two before the rash appears.
These can include:
- feeling tired and generally unwell
- nausea (feeling sick)
- a high temperature (fever) of 38C (100.4F) or over
- aching, painful muscles
- loss of appetite
Not everyone has these symptoms. They tend to be more common and more severe in older children and adults with chickenpox.
The chickenpox rash develops in three main stages.
Stage 1: spots
The rash starts off as small, raised red spots.
The spots often first appear on the face or trunk before spreading to other parts of the body.
There may just be a few spots or there may be hundreds covering most of the body.
Sometimes spots can appear on the palms of the hands, the soles of the feet, inside the ears or mouth, or around the bottom or genitals.
Stage 2: blisters
During the following hours or the next day, the spots develop a fluid-filled blister on top.
The blisters may be very itchy, but it's important not to scratch them.
Scratching could spread the infection to others and increases the chances of complications such as a more serious skin infection.
Stage 3: scabs and crusts
Over the next few days, the fluid in the blisters turns cloudy and the blisters begin to dry out and scab over.
New spots may keep appearing for a few days after the rash begins, so there may be a mix of spots, blisters and scabs at the same time.
Chickenpox is contagious until every blister has scabbed over, which usually occurs by around five or six days after the rash started.
The scabby crusts will fall off by themselves over the next week or two.
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Chickenpox is usually mild and can be treated at home. Most people feel better within a week or so.
There's no cure, but the treatments below can help relieve the symptoms while the body fights the infection.
It's also important to take steps to prevent chickenpox spreading, such as staying off work or school until the last blister has dried and crusted over.
Use paracetamol if you or your child have a high temperature (fever) and feel uncomfortable.
Paracetamol is safe for most people to take – including pregnant women and children over two months of age. Special liquid versions are available for young children and babies.
Don't use anti-inflammatory painkillers, such as ibuprofen, as they can sometimes make people with chickenpox very ill. Never give aspirin to a child under 16 as it can be dangerous for them.
Always read the packet or leaflet that comes with the medicine to check if it's suitable and how much to take. Speak to a pharmacist or your GP if you're unsure.
Prevent itching and scratching
Chickenpox can be very itchy, but it's important not to scratch the spots as it can increase the chances of the skin becoming infected with bacteria and could result in scarring.
It can help to:
- keep nails short and clean
- tap or pat the skin instead of scratching it
- wear cotton gloves at night (or socks over hands)
- bathe in cool or lukewarm water – dab or pat the skin dry afterwards, rather than rubbing it
- wear loose, smooth cotton clothing
You can also buy calamine lotion, moisturising creams, cooling gels or an antihistamine medicine called chlorpheniramine to help reduce itching and soothe the skin.
Food and drink
It's important to drink plenty of fluids to avoid dehydration.
Water is better than sugary, fizzy or acidic drinks – particularly if you or your child has chickenpox spots in the mouth.
Sugar-free ice lollies are also a good way of getting fluids into children and can help soothe a sore mouth.
Avoid sharp, hard, salty or spicy foods that may make the mouth sore. Soft, cool foods are best, such as soup that has been left to cool down.
If you breastfeed or bottle feed your baby, continue to give them feeds regularly.
Stronger treatments from a doctor
Antiviral medication or a treatment called immunoglobulin may be recommended if you're at risk of developing severe chickenpox.
Those at risk include:
- pregnant women
- adults, especially those who smoke
- newborn babies under four weeks old
- people with a weakened immune system (the body's defence system), such as people with HIV, those taking high doses of steroid medication and those having chemotherapy
An antiviral medicine called aciclovir may be recommended if you're at risk of severe chickenpox and you already have symptoms.
It ideally needs to be started within 24 hours of the rash appearing. It doesn't cure chickenpox, but makes the symptoms less severe.
It's normally taken as tablets five times a day for seven days.
Immunoglobulin is a treatment given by injection that can help prevent severe chickenpox if you've been exposed to someone with the infection but don't have any symptoms yet.
It's sometimes given to pregnant women, people with a weakened immune system and newborn babies who've been exposed to the chickenpox virus and haven't had the infection before.
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Chickenpox is usually mild and passes without causing any serious problems, particularly in children.
But sometimes complications can occur.
These are more common in:
- adults, especially those who smoke
- pregnant women
- newborn babies less than four weeks old
- people with a weakened immune system, such as people with HIV, those taking high doses of steroid medication and those having chemotherapy
The most common complication of chickenpox is the skin becoming infected with bacteria. This is more likely to happen if you or your child scratches your spots.
The skin may be infected if it becomes:
- painful and tender
Contact your GP if you think your or your child's blisters have become infected. You may need antibiotics to treat the infection.
Occasionally, the chickenpox virus can spread to the lungs and cause pneumonia.
This is more common in adults (particularly those who smoke), pregnant women and people with weakened immune systems.
Symptoms of pneumonia can include:
Contact your GP as soon as possible if you think you or your child may have developed pneumonia. You may need to be treated in hospital.
Infections of the brain or nerves
In rare cases, chickenpox can lead to more serious infections of the brain and spinal cord in children, people with weakened immune systems and pregnant women.
This can cause:
- a lack of energy
- seizures (fits)
- severe headaches
- a stiff neck
- behavioural changes
- problems with walking, balance or speech
Seek medical advice as soon as possible if you or your child develops any of these symptoms after having chickenpox. Treatment in hospital will usually be needed.
If you become infected with chickenpox for the first time while you're pregnant, there is a small risk of potentially serious complications affecting your baby.
The risks depend on when you pick up the infection.
- Infection during the first 28 weeks can result in a rare but serious condition called congenital varicella syndrome, which may cause shortened limbs, vision problems (such as cataracts), brain damage and scarring.
- Infection during weeks 28 to 37 can mean your baby is at risk of developing shingles at some point after they're born.
- Infection a week before to a week after birth can mean your baby is a risk of a severe and potentially life-threatening chickenpox infection.
Contact your GP as soon as possible if you are pregnant or have given birth recently and you think you may have chickenpox, or have been exposed to someone with the infection.Your GP can do a blood test to check if you're already immune to the infection and can arrange for you to have stronger treatments to prevent a severe infection.
Shingles and chickenpox
About one in every three people who've had chickenpox will develop a related condition called shingles later in life.
This occurs when the chickenpox virus, which lies inactive in the body after a chickenpox infection, becomes reactivated for some reason and causes a painful, blistery rash.
Read more about shingles.
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Chickenpox is highly contagious and can make some people very ill, so it's important to try to avoid spreading it to others.
Some of the things you can do are outlined below.
Stay away from school or work
If you or your child has chickenpox, stay away from school, nursery or work until all of the blisters have dried up and scabbed over.
This usually happens five or six days after the rash first appears.
You may continue to have spots on your skin for another week or two, but you're no longer contagious if the spots are dry and scabby.
Avoid contact with people at risk
Certain people are at a higher risk of becoming seriously ill if they become infected with chickenpox.
- pregnant women
- newborn babies
- people with a weak immune system (the body’s defence system), such as people with HIV, those taking high doses of steroid medication and those having chemotherapy
If possible, try to avoid contact with people from these groups until the blisters have scabbed over and you're no longer contagious.
Clean and wash regularly
Chickenpox can be spread through contact with objects that have been contaminated with the virus, such as toys, bedding or clothing.
If someone in your house has chickenpox, you can help stop the virus spreading by cleaning any objects or surfaces with a disinfectant and making sure that any infected clothing or bedding is washed regularly.
Travelling on a plane
If you or your child have chickenpox, you may not be allowed to fly until all the blisters have dried and scabbed over. It's a good idea to inform the airline of your situation and check whether they have a policy about when they allow people with chickenpox to fly.
It is also important to let your travel insurer know if you or your child have chickenpox. You need 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.
There is a vaccination against chickenpox, but it's only given to people who are at a very high risk of spreading the infection to vulnerable people.
These include healthcare workers and people living with someone who has a weakened immune system.
Read more about the chickenpox vaccination.
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The information on this page has been adapted by NHS Wales from original content supplied by NHS Choices.
Can I get chickenpox more than once?
Yes, it is possible to get chickenpox more than once, but this is extremely rare.
Most people who have had chickenpox won't get it again because they're immune to it for life.
However, some people who have had chickenpox will develop a related condition called shingles later on. This is caused by the chickenpox virus being reactivated, usually several decades later.
How are chickenpox and shingles connected?
Chickenpox and shingles are both caused by the same virus: the varicella-zoster virus.
In some people who have had chickenpox, the virus can become active again later in life and cause shingles.
You can't catch shingles from someone else. However, you can catch chickenpox from someone with shingles if you haven't had chickenpox before.
What are the risks of chickenpox during pregnancy?
Chickenpox during pregnancy can cause complications, both for the pregnant woman and the unborn baby. However, the actual risk of any complications occurring is low.
It's rare to get chickenpox when you're pregnant. In the UK, it's estimated that just 3 in every 1,000 women (0.3%) catch chickenpox during pregnancy.
Most pregnant women who get chickenpox recover, with no harmful effects on the baby.
When to get medical advice
Seek advice from your GP or midwife immediately if you're pregnant and:
- you think you may have chickenpox
- either you've never had chickenpox or you're not sure, and you've been near someone that has it (even if you have no rash or other symptoms)
- you get chickenpox within seven days of giving birth
Complications for pregnant women
You have a higher risk of complications from chickenpox if you're pregnant and:
- have a lung condition, such as bronchitis or emphysema
- are taking or have taken steroids during the last three months
- are more than 20 weeks pregnant
There is a small risk of complications in pregnant women with chickenpox. These are rare and include:
Complications that arise from catching chickenpox during pregnancy can be fatal. However, with antiviral therapy and improved intensive care, this is very rare.
Complications for the unborn baby
Complications that can affect the unborn baby vary, depending on how many weeks pregnant you are. If you catch chickenpox:
- Before 28 weeks pregnant: there's no evidence you are at increased risk of suffering a miscarriage. However, there's a small risk your baby could develop foetal varicella syndrome (FVS). FVS can damage the baby's skin, eyes, legs, arms, brain, bladder or bowel.
- Between weeks 28 and 36 of pregnancy: the virus stays in the baby's body but doesn't cause any symptoms. However, it may become active again in the first few years of the baby's life, causing shingles.
- After 36 weeks of pregnancy: your baby may be infected and could be born with chickenpox.
Complications for the newborn baby
Your baby may develop severe chickenpox and will need treatment if you catch it:
- around the time of birth and the baby is born within seven days of your rash developing
- up to seven days after giving birth
What should I do if I'm pregnant and I've been near someone with chickenpox?
It depends on whether you’ve had chickenpox or not. Most pregnant women in the UK and Ireland have had chickenpox and are immune to the virus that causes it. If you've had chickenpox yourself, there's no need to worry about contact with it when you're pregnant.
What if I haven’t had chickenpox?
You should get advice from your GP or midwife immediately, even if you have no rash or other symptoms, if:
- you’re pregnant and you know that you haven’t had chickenpox, or you’re not sure, and
- you’ve been near someone with chickenpox or shingles.
Rarely, chickenpox during pregnancy can cause complications both for the woman and her baby.
You should also get medical advice straightaway if:
- you’re pregnant and you think you may have chickenpox, or
- you develop any rash when you’re pregnant, including a rash that develops after contact with someone who has chickenpox or shingles.
Chickenpox and shingles
In some people, the chickenpox virus can become active again later in life, when it causes shingles.
If you’re not immune to the chickenpox virus, it’s possible to catch chickenpox from someone who has shingles. However, this risk is very small.
What if I have had chickenpox?
If you’ve already had chickenpox, it’s extremely unlikely that you will get it again. However women who have come into contact with someone with chickenpox or shingles should see their GP if a rash develops.
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Last Updated: 19/04/2017 11:41:00