Chickenpox

Chickenpox is a common, infectious disease. It is caused by a virus called varicella zoster.

It mostly affects children under the age of 10, but you can get it at any age.

There’s no cure for chickenpox. The virus usually clears up by itself without any treatment.

Try and avoid coming into contact with other people if you or your child have chickenpox. Especially avoid coming into contact with pregnant women and babies.

You can get a vaccine to protect you from chickenpox

Red spots and chickenpox

  1. Chickenpox starts with red spots. They can appear anywhere on the body. They become extremely itchy after about 12 to 14 hours.
Red spots appear and become extremely itchy
  1. The spots fill with fluid. The blisters may burst. They might spread or stay in a small area.
Chickenpox spots become blisters
  1. The spots scab over. More blisters might appear while others scab over. This happens after a day or 2.
Chickenpox spots scab over

After 1 to 2 weeks, the scab will fall off naturally.

New spots can keep appearing in waves for 3 to 5 days after the rash begins. Different groups of spots may be at different stages of blistering or drying out.

Chickenpox is very itchy and can make children feel miserable, even if they do not have many spots. Chickenpox is usually much worse in adults.

Other symptoms of chickenpox

You might get symptoms before or after the spots, including:

  • a high temperature above 38 degrees Celsius
  • aches and pains, and generally feeling unwell
  • loss of appetite

Diagnosing chickenpox

You or your child do not usually need any medical tests to diagnose chickenpox. A blood test can show if you have had it before and are immune.

The blood test checks if you are producing the antibodies to the chickenpox virus. If you are, you'll be okay. If you do not have the antibodies, you could develop chickenpox symptoms.

When to get medical help

Adults

Speak to your GP if:

  • you're not sure it's chickenpox
  • the skin around the blisters is red, hot or painful - this is a sign of infection

Ask for an urgent GP appointment if:

  • you're an adult and have chickenpox
  • you're pregnant, haven't had chickenpox before and you've been near someone with it
  • you have a weakened immune system and you've been near someone with chickenpox

Always phone ahead and inform your GP that you think it's chickenpox before going in. They may give you a special appointment time if other patients are at risk.

Children

Contact your GP immediately if you think your child has chickenpox and they:

  • are under 1 month old
  • have heart or lung disease
  • are on chemotherapy, immunosuppressants or steroids
  • have a disease that affects their immune system - like HIV or a bone marrow disease

Ask for an urgent GP appointment if your child has chickenpox and they have:

  • redness, pain and heat in the skin around a blister or spot
  • breathing problems
  • symptoms of dehydration
  • certain skin conditions like eczema
  • headaches that don't go away after giving paracetamol, or are getting worse

Always phone your GP surgery if you think your child has chickenpox before bringing your child in to see them. This is so they can take precautions to prevent the virus from spreading to other people in the surgery.

Call 999 or 112 if your child has chickenpox and they have a fit or seizure.

Call your nearest hospital emergency department that treats children if your child has chickenpox and they:

  • have trouble walking or are very weak
  • are drowsy or hard to wake

Make sure the hospital emergency department or the ambulance call-taker know that your child has chickenpox, so they can take appropriate precautions to prevent the infection from spreading.

Chickenpox in pregnancy

Contact your GP or midwife immediately if you’re pregnant and you:

  • think you have chickenpox
  • have spent time with someone who later developed chickenpox

Your GP or midwife will take steps to protect you and your baby depending on what stage you are at in your pregnancy.

Most people have chickenpox in childhood. So it's rare to get chickenpox when you're pregnant and the chance of it causing complications is low. Most pregnant women who get chickenpox recover, with no harmful effects on the baby.

In some cases, chickenpox in pregnancy can cause health problems for mothers and babies. There's a small risk of your baby being ill when it's born.

The risk of these complications increases if you get chickenpox after 36 weeks of pregnancy.

If you have chickenpox

Go to your maternity hospital urgently if you have chickenpox and other symptoms like:

  • bleeding from your vagina
  • breathing problems or other chest symptoms like a bad cough or noisy breathing
  • a headache, stiff neck, difficulty looking at bright lights or drowsiness (these may be signs that chickenpox is affecting your brain or nervous system)
  • vomiting or feeling sick
  • a rash that is bleeding

Phone ahead to tell the maternity hospital that you're coming. They can take precautions to stop chickenpox from spreading to other pregnant women. For example, they might have a different space for you to wait in away from the main waiting room.

To stop your symptoms from getting any worse, you may need:

  • antiviral medicine through a drip
  • immunoglobulin treatment - a blood-based treatment that contains antibodies to help fight the virus

How to treat chickenpox

There are things you can do to ease the itching. You can also take medication to help with the pain and discomfort.

Ease pain and discomfort

You or your child can take paracetamol.

If you or your child has chickenpox don't use ibuprofen unless your GP has told you to. This is because using ibuprofen can increase the risk of serious skin infections.

Do not use aspirin or products containing aspirin. Do not give children under 16 aspirin - it can be very dangerous.

Stop the itching

Chickenpox can be very itchy. Try not to scratch the spots as it can cause scarring.

Keep your child's finger nails clean and short. You can put socks on their hands at night to stop them scratching.

Use cooling creams or gels from a pharmacy, if your child's skin is very itchy or sore.

Speak to a pharmacist about using antihistamine medicine to help the itching.

You could also bathe your child in lukewarm water - a hot bath can make the itch worse.

Keep hydrated

Drink plenty of water to avoid dehydration. Ice lollies are a good way of getting fluids into children. They also help to soothe their sore mouth if they have chickenpox spots in it.

Wear cool clothes

Dress your child in loose-fitting clothes. Cotton fabrics are best and will help stop their skin from becoming sore and irritated.

How chickenpox spreads

You can catch chickenpox by being in the same room as someone who has it.

It's also spread by touching clothes or bedding that has fluid from the blisters on it.

Chickenpox can spread to others as long as there are any spots which are not crusted and dried.

How long chickenpox is infectious for

Chickenpox is infectious from 2 days before the spots appear to until they have crusted over, usually 5 to 7 days after they first appeared.

It usually takes one to 3 weeks from the time you were exposed to chickenpox for the spots to start appearing. Adults can return to work once their spots are crusted and dried over, and they feel well enough to go back to work.

Keep your child off school, pre-school or childcare until their spots are dry. Once the spots are crusted and dried they can go back to school as they stop being infectious.

Stop chickenpox spreading

Chickenpox can be dangerous for some people.

Avoid contact with:

  • pregnant women
  • newborn babies
  • anyone who has a weak immune system

People may have a weak immune system if they are having chemotherapy (a treatment for cancer). Taking steroids can also weaken someone’s immune system.

Wipe down or sterilise any objects you or your child have touched, such as children's toys.

Wash infected bedding or clothing.

Travelling after chickenpox

Many airlines will not allow you to fly with chickenpox. Check with your airline before you travel.

Shingles and chickenpox

You cannot catch shingles from someone with chickenpox. But if you have not had chickenpox before you can catch it from someone with shingles.

When you get chickenpox, the virus stays in your body. It can cause shingles if your immune system is low.

This can be because of:

  • stress
  • certain conditions
  • treatments like chemotherapy
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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.

Page last reviewed: 4 November 2021
Next review due: 4 November 2024

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