This website is produced and funded by MSD. It is intended to provide general educational information and does not take the place of professional medical advice.
The medical name for chickenpox is varicella because it is caused by the varicella zoster (VZ) virus. It’s a highly infectious disease, which means it’s easy to catch from someone who already has chickenpox.
The good news is that, in most cases, once you’ve had it, your body is able to protect you from catching it again.
of adults in Ireland are immune to chickenpox because they had the disease as child.1
Other diseases can cause rashes, so you shouldn’t simply assume it’s chickenpox.
The illness usually starts with one to two days of fever, aches and pains and feeling out of sorts.
Then, an itchy, spotty rash develops, turning from spots to blisters to scabs and crusts. How many spots appear varies from person to person; some people hardly have any, while others are covered head to toe.
The infection is spread in the fluid found in chickenpox blisters and the droplets in the coughs or sneezes of someone with the infection.
Chickenpox is contagious from one to two days before the rash appears until all the blisters have scabbed over. This takes about five days.
Because chickenpox is highly contagious, you should try to prevent spreading it by avoiding contact with others, particularly those at higher risk of complications such as pregnant women and people with weakened immune systems.
A little one with chickenpox will need around
so you may have to take time off work to look after them.1
If you are due to take a flight, you may not be allowed to fly until the last blister has scabbed over, so check with the airline. If you are not contagious but the rash is still present, you may need a doctor’s certificate.
Chickenpox is usually mild, but occasionally it can lead to serious complications, especially in adults, pregnant women, newborn babies and people with weakened immune systems.
People in these high-risk groups are more likely to experience complications such as secondary infections. For pregnant women, there is a small risk of the infection being passed to the unborn baby or causing birth defects.
Post exposure prophylaxis with varicella antibodies is recommended in individuals who fulfill all the following three criteria2:
If you develop a skin or lung infection, you will need treatment with antibiotics. In severe cases, you may need to be hospitalised.
For people at high risk of complications, doctors sometimes prescribe medications to shorten the duration of the infection and reduce the risk of complications. These should be given within 24 hours of the first appearance of the rash.
There may not always be signs of chickenpox complications. However, you should look out for swollen or painful skin, difficulty breathing or dehydration.
If you see any possible signs of complications, contact your GP, Practice Nurse or Pharmacist immediately.
If you have had chickenpox, you have a greater risk of developing shingles in later life. This can happen when the immune system is low (e.g. due to stress or certain medical conditions) and the chickenpox virus becomes reactivated. Though they are both caused by the same virus, chickenpox and shingles are different diseases.
Chickenpox is usually mild and clears up in about a week. However, some people can become seriously ill and need to see a doctor.
Contact your GP, Practice Nurse or Pharmacist if:
You should also get advice if you are originally from a country near the equator and have been exposed to chickenpox, as you are less likely to have been exposed to the disease as a child. Chickenpox is more common in adults from these areas, and you may need treatment to stop you becoming seriously ill.
There is no cure for chickenpox and the virus usually clears up by itself without any treatment.
Your pharmacist can advise about medicines that may help relieve itching or reduce pain and discomfort, but things will usually clear on their own after a few days. If complications develop, your doctor will decide on the appropriate treatment.
If you need to book a doctor's appointment, tell the receptionist that your child has chickenpox.
You may need to arrange a special appointment time to avoid infecting other patients.Paracetamol is the preferred painkiller for treating the associated symptoms of chickenpox. This is due to a very small risk of non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, causing adverse skin reactions during chickenpox.
It can cause skin infections or permanent scarring. If your child can't stop scratching, keep their fingernails short and put gloves or socks on their hands, especially at night.
Speak to your pharmacist about using cooling creams or gels to relieve itching.
Drink plenty of fluids to stay hydrated. Try ice lollies if your child isn't drinking. A diet of soft, cold foods is best if chickenpox sores develop in the mouth.