Everything you need to know about Chicken pox

by Adejumoke Ilori |
Updated on

Everyday illness is a normal part of childhood – to be honest, it’s absolutely natural for your little one to pick up a stomach bug or a cold.

And, this includes Chicken pox, also called varicella, a disease caused by a virus that can easily spread to others, but classed as a mild illness that will improve on its own.

So, don't panic because here, you'll be able to find out its causes, symptoms and treatment with our expert overview of the condition.

What is chicken pox?

Chicken pox is a common childhood illness that features a rash of itchy red spots that turn into fluid filled blisters and eventually form scabs and drop off. Some children have just a few spots while others are covered in them. It is caused by the varicella zoster virus, is most common in children under ten and is easily spread in nurseries and schools. It is often confused with measles which has slightly different symptoms.

Although chicken pox is common, it can leave your little one feeling rather uncomfortable with itchy red spots. They usually clear up in a week or so, but it can be dangerous for some people, including pregnant women, newborn babies and those with a weakened immune system. 90 per cent of adults are immune to chicken pox because they’ve already had it as a child but if you do have it as an adult the symptoms can be more severe.

What are the signs and symptoms of chicken pox?

Before the spots appear many children have mild flu-like symptoms including:

  • a headache

  • temperature (in the 38.3° to 38.8° region)

  • feeling sick

  • aching muscles

  • clusters of small itchy red spots commonly starting on the back, belly or face and later moving to the scalp, chest, arms and legs though they can appear anywhere - even in the mouth, genitals and ears. The spots can appear worse in children with eczema.

The spots quickly become blisters and are at their itchiest 12-14 hours after they appear. New spots appear in waves for three to five days. They generally clear up within a week or two of scabbing over. It's worth noting, your little one is contagious until all the blisters have scabbed over, which is normally five to six days after the rash first appeared.

The virus that causes chicken pox lays dormant in your body’s nerve tissues and can return in later life as shingles. It is possible to catch chicken pox from someone who has shingles but not the other way round.

What does the chicken pox rash look like?

Baby with chicken pox

The rash will begin as small red bumps on the skin that look like insect bites or little spots. These red bumps will usually appear on the skin over 2-4 days before developing into small blisters filled with fluid. The blisters will then turn into scabs that are usually red or brown in colour.

What causes chicken pox?

Chickenpox is caused by a virus called varicella-zoster (varicella is the medical name for chickenpox). If your baby hasn’t already had chicken pox, there’s a 90 per cent chance of her getting it if she comes in contact with the infection.

This contagious bug is sneezed and breathed around, just like the common cold. It takes seven to 21 days for the symptoms of chicken pox to show after your baby comes 
into contact with the virus.

You can also catch chicken pox from:

  • touching a contaminated surface

  • touching contaminated bedding or toys (which is why it is so common for all of your children to suffer with chicken pox at the same time)

  • touching the chicken pox or shingles rash

  • face-to-face contact with an infected person

  • being in the same room as someone with chicken pox for more than 15 minutes

What can you do if your child has chicken pox?

Call your GP so the infection can be noted on your child’s medical records, but don’t take her to the surgery – chickenpox is highly infectious, so unless your baby is severely unwell, your GP will probably ask you to treat your baby at home. Your baby will be infectious from around two days before the rash appears.

When it comes to treating the chicken pox and helping your baby feel more comfortable, try the following:

  • Use paracetomol to relieve fever and discomfort. The NHS urges parents NOT to use medications containing ibuprofen as these can make those suffering with chicken pox feel much worse.

  • Use calamine lotion and cooling gels to soothe the itching and dress your baby in loose cotton clothing.

  • Pat the skin rather than scratching it - it's important to try and discourage your toddler from scratching as this can cause problems later on.

  • Stay hydrated.

  • Encourage your todler to cover her mouth if she coughs or sneezes to prevent other people catching the bug.

  • If your toddler has blisters in their mouth, sugar-free ice-lollies are particularly soothing.

Worried about chicken pox? When you should phone your GP

Complications are rare in healthy children, but it's still good to know when to contact your GP. According to the NHS, you should phone your GP if:

  • You're not sure if yours or your baby's rash is chicken pox - if in doubt, check as chicken pox can be highly contageious and dangerous to pregnant women and elderly people.

  • Your baby is less than four weeks old and you are worried she might have chicken pox.

  • Your baby's symptoms haven't improved in six days.

  • You're an adult and you've got chicken pox.

  • If the area surrounding a blister becomes red, sore or hot - this could be a sign of infection.

  • If your toddler is dehydrated.

  • Very rarely chicken pox can lead to complications of the brain and spinal cord such as meningitis or encephalitis. Signs can include drowsiness, vomiting, headache, a stiff neck, seizures and behavioural changes. If you notice any of these speak to your GP immediately.

Chicken pox in pregnancy

If you are pregnant and your child contracts chicken pox you should also see your doctor. If you are infected with chickenpox during the first 28 weeks of your pregnancy there is a small risk that your unborn baby could develop a condition known as foetal varicella syndrome, which can cause scarring, eye defects (such as cataracts), shortened limbs and brain damage.

What is the chicken pox vaccine?

The chicken pox vaccine protects against the varicella zoster virus that causes chicken pox. This is not currently part of the routine NHS vaccination programme and is only offered to those in close contact with someone who is particularly vunerable to chicken pox. There are two chickenpox vaccines currently available to children 12 months and over. The brand names being VARIVAX and VARILRIX.

At present those offered it on the NHS are normally patients who:

  • take long-term steroid tablets

  • are having chemotherapy

  • have had their spleen removed

  • have had an organ transplant and are using immunosuppressant medicines

  • have been diagnosed with HIV or AIDS

The NHS also recommended the vaccination for:

  • brothers and sisters of a child who has leukaemia

  • a child whose parent is having chemotherapy

Our childcare expert Fi Star Stone weighed up the pros and cons of purchasing the chicken pox vaccine here.

What is the difference between chicken pox and shingles?

Chicken pox and shingles are connected as they are both caused by the varicella-zoster virus. Some people who have chicken pox as a baby will still catch shingles when they are an adult, but you cannot get chicken pox twice. As we mentioned above, you cannot catch shingles from someone else, however you can catch chicken pox from someone suffering from shingles if you have not had chicken pox before.

According to the NHS, it is estimated one in four adults will suffer from shingles during their lifetime. It is not known why some people catch shingles, but in most cases it is thought to be because of a weakened immune system.

According to Dr Deborah Lee: "Chickenpox is a viral illness caused by the varicella-zoster virus (VZV). The majority of children catch it before they are 5, but almost always before they are 10. The most common time to have chicken pox is in winter or spring  - so between March and May."

"Chickenpox is highly contagious – meaning it spreads very easily. When an infected person coughs or sneezes, VZV-infected mucous droplets are propelled into the air, which another person then easily inhales into their lungs. The virus can also be directly transmitted by touching mucous, saliva or blister fluid from an infected person."

"The VZ virus also causes herpes zoster – shingles. But the nature of the infection is different.  Shingles are due to the reactivation of a previous chickenpox infection and usually affect only one dermatome – one nerve supplying a specific area of skin."

"A person can catch chicken pox from shingles, but you can’t catch shingles from chicken pox. Or putting it another way  - you have to have had chicken pox to get shingles. You can’t have shingles if you haven’t had chicken pox.", Dr Deborah Lee said.

What are chickenpox symptoms?

First symptoms –The chicken pox illness often begins with ‘flu-like ‘ symptoms such as fever  - 101°–102°F (38.3°–38.8°C), headache, aching muscles, a sore throat, a tummy ache, feeling unwell and loss of appetite. Sometimes, these symptoms occur before the onset of the rash a day or two later.

1-2 days later – The chicken pox spots appear. They can be anywhere on the body and can be singular or in crops. They are typically on the face and scalp, the trunk and belly, behind the ears, and they may be inside the mouth and ears, on the palms and soles, and on the nappy region. The spots are extremely itchy.

Note that especially in children, the rash may suddenly appear, and be the first sign of the illness, without any preceding symptoms.

The course of the illness  - The spots start as little raised red bumps that reassemble insect bites, but within 12-24 hours, they have a vesicle (blister) containing clear fluid at the centre. Over a few days, the blister becomes cloudy, then the spot becomes dry and crusty, scab forms and eventually the scab falls off. New spots continue to appear over the next 3-5 days. The child/person is contagious until the last crop of spots is dry.

Often chicken pox infection in children is a mild illness. In children, there may be no early symptoms and the first sign of chicken pox can be the appearance of the rash. Adults tend to have more severe symptoms than children, and more often have a high fever.

In the vast majority of cases, chicken pox clears up by itself, but rarely there can be serious complications. The most common are  -

  • Secondary bacterial infections causing sepsis – including Streptococcus A

  • Pneumonia

  • Encephalitis

  • Bleeding issues resulting in haemorrhage

The chickenpox rash?

In babies and children, the diagnosis of chickenpox is usually a straightforward, clinical diagnosis. However, the differential diagnosis includes

  • impetigo  - a bacterial skin infection

  • herpes simplex – a viral skin infection

  • scabies  - caused by the scabies mite

  • infected insect bites – these can become secondarily infected by bacteria such as staphylococcus aureus of group A streptococcus

  • hand, foot and mouth disease  - caused by a coxsackie virus

  • a drug reaction (side effect)

  • dermatitis herpetiformis – an autoimmune skin condition associated with coeliac disease.

  • congenital syphilis – this is extremely rare

The kinds of chickenpox vaccines?

There are two currently available chicken pox vaccines

  • Varilrix

  • Varivax

Both are live vaccines – meaning they contain a weakened form of the VZ virus. They are recommended for persons aged 12 months of age and older but can occasionally be used from 9 months of age.

At present in the UK, babies are not routinely immunised against chicken pox,  but the situation is up for debate.

If you think you or your child should have the chicken pox vaccine, speak to your GP. Not all GP surgeries offer it, and you may need to pay for it privately. The NHS only vaccinates high-risk groups against chicken pox, such as those who come into contact with others who have a weakened immune system.

The VZV vaccine is given in the arm. Two doses are needed, four to eight weeks apart.

You should avoid getting pregnant within one month of having the vaccine.

For more information

What are the chickenpox stages?

Stage 1 – The appearance of the red, bumpy skin rash.

Stage 2 – Over the next 1-2 days, the spots become blistered with blisters containing clear fluid.

Stage 3 – Over the next 3-5 days, the blisters become cloudy, the spots become crusty and dry, scabs form and the scabs then fall off.

Note that the infected person has spots at all different stages of development at the same time. New crops of spots keep appearing for 3-5 days after the onset.

What are the chicken pox treatments?

In the vast majority of cases, antiviral drugs are not required to treat chicken pox. Patients typically recover within 1-2 weeks without them. Antivirals are reserved for the most severe cases, such as seriously ill adults, very young babies or those with a weakened immune system.

Chickenpox is generally managed with supportive treatment only.

  • Paracetamol can be given to lower the temperature and ease muscular pain. Aspirin should not be used in children under the age of 16 because of the risk of Reye’s syndrome.

  • Calamine lotion can be dabbed onto the spots to help relieve itching. Taking a cool bath can help. Adding a tablespoon of salt to the bath water, or a handful of oats tied in a muslin can also help stop itching. Pat the skin dry afterwards – don’t rub.

  • Sometimes, antihistamines such as Piriton can be used but ask advice from your pharmacist. They can also make children sleepy.

  • Children and adults with chickenpox should be kept at home and stay away from nursery/school or work until they are no longer infectious.

  • If antivirals are given this is aciclovir.

  • Make sure the person stays well hydrated and gets plenty of rest.

How long does chicken pox last?

Chicken pox usually lasts 1-2 weeks. The first symptoms occur 10-21 days after being exposed to the VZV virus. The spots continue to appear for 3-5 days. It takes 5-7 days for the spots to crust over, scab and for the scab to fall off. The person remains infectious until the last crop of spots is dry.

Can you get chicken pox twice?

Rarely, you can get chicken pox twice. If this happens it could indicate you had chicken pox before you were 6 months old, you only had a very mild illness or you have a weakened immune system.

Chickenpox incubation period?

The incubation period is 10-21 days after being in contact with the VZ virus.

The person is believed to be contagious from 1-2 days before the rash first appears and until all the spots have crusted over and become dry.

What does chicken pox look like?

Chickenpox is a red, bumpy rash that can occur anywhere on the body. The red bumps turn into clear, fluid-filled blisters which then become cloudy, dry out, crust over, and form scabs.

Can I go to work if my child has chickenpox?

The NHS recommendation is that adults can still go to work if their child has chicken pox, so long as they have appropriate care for their child in place. Chickenpox is so common most adults have had it in childhood and have lifelong immunity.

If you think you might have chicken pox you should stay at home and keep away from pregnant women, newborn babies or anyone with a weakened immune system.

When is chickenpox contagious?

Chickenpox is contagious from 1-2 days before the rash appears until 24 hours after the last crop of spots is crusted and dry.

Can you fly with chicken pox?

It’s not sensible to fly if you have chicken pox as the virus is transmitted in respiratory secretions and there is a high risk of infecting others on the plane.

Some airlines have regulations that prohibit travelling with chicken pox. For example, TUI state a person cannot fly until 7 days after their last crop of spots has disappeared, and you may need a GP letter to support this.

How long does chickenpox live on surfaces?

The VZ virus does not live for long outside the body on other surfaces. It is inactivated by cleaning with usual household bleach and by washing with standard detergents at 60°C.

Can you use Sudocrem on chicken pox?

Sudocrem can be used for chicken pox. It contains zinc oxide which can help soothe itching as it prevents the release of histamine from mast cells. Histamine is a cell-signalling molecule that is released in allergic and inflammatory reactions. Use a cotton bud to dab a little onto each spot.

How long for chicken pox to scab?

It takes around 5 days for a chicken pox spot to blister, dry out and scab. Because new spots keep appearing for 5 days or more, a person will have spots at all different stages of development at the same time. On average it takes 10 -14 days for all the spots to have appeared, healed and disappeared.

How to get rid of chicken pox?

There's no cure for chicken pox. It's important to treat it symptomatically and take steps not to allow the infection to spread to anyone at high risk from the infection – such as a pregnant woman, a newborn baby or anyone with a weakened immune system.

How to stop chickenpox itching?

Chickenpox spots are incredibly itchy. Scratching them increases the risk of scarring and secondary infection so it’s important to try not to scratch them. The following can help –

  • Keep their fingernails short.

  • Give them a tepid bath – not too hot as this can make itching worse.

  • Add colloidal oatmeal or salt to the bath water.

  • Don’t soak for too long – then pat the skin dry.

  • Apply calamine lotion using a cotton pad and dab it on.

  • You could try dabbing Sudocrem on the spots using a cotton bud.

  • Try an antihistamine – ask the pharmacist for advice.

  • Keep your child occupied with games, books or movies to help take their mind off the itching.

Is chicken pox dangerous for babies, and why?

Young babies are at risk from chickenpox as they have a relatively weak immune system. The antibodies they obtained from their mother, through the placenta and early breast milk, have mostly disappeared by 3 months of age, leaving them susceptible to a wide range of infections including VZV.

Is chicken pox dangerous when pregnant, and why?

If a pregnant woman contracts chickenpox this can be dangerous for her and her unborn baby. The majority of pregnant women will be immune to chicken pox having had it in childhood.

If you have not had chickenpox in childhood, or have come from a tropical or subtropical country, and have been exposed to chickenpox in pregnancy, you should be tested to see if you are immune to VZV.

If the mother has chickenpox during the first 20 weeks of pregnancy, the baby has a risk of developing fetal varicella syndrome (FVS) – which causes eye, limb, brain and gastrointestinal malformations. It has been reported in mothers who have had chickenpox up to 28 weeks gestation.

If a pregnant woman gets chicken pox in the last 3 weeks of pregnancy, the baby may develop neonatal varicella infection - which is a serious infection and can be fatal.

If a woman knows she is not immune to chicken pox, she should avoid contact with anyone with chickenpox during her pregnancy.

If she does come into contact with chickenpox during pregnancy, she should contact her midwife right away.  She can be tested to check her immunity to VZV, and given VZ immunoglobulin – which is the antibody to VZV her body needs to make to mount a defence against the VZ virus.

The chickenpox vaccine

The chickenpox vaccine is not recommended for babies under 9 months old. It may be considered for anyone who is

  • Over 9 months old

  • Not had chicken pox in the past

  • In regular contact with anyone with a weakened immune system, such as a child with leukaemia or anyone having chemotherapy.

"Note that the chicken pox vaccine is a live vaccine and should not be given to anyone with a weakened immune system, including babies under 9 months of age, pregnant women and those receiving chemotherapy.", Dr. Deborah Lee added.

We also spoke to Dr. José Costa who spoke about the chicken pox treatments: "Acyclovir might be advised for some people. This will include any pregnant women who have never had chickenpox. Those with a weakened immune system, who are over 12 years old, or who have a chronic skin or lung condition will also benefit from taking acyclovir.", he said.

Dr. Costa also added that: "traditional creams, like calamine lotion are still the best to help ease the itching and dry the lesions. Chlorphenamine (often sold as Piriton) can also be given to decrease itching and help your child sleep. Cool baths with either baking soda or uncooked oats can also help to ease discomfort."

"Paracetamol is the best choice to help relieve pain and to reduce a high temperature."

"Do not give your child aspirin or ibuprofen. Giving aspirin to someone with chicken pox can increase the risk of developing Reye’s Syndrome (a rare condition that can lead to swelling of the tissues, including the brain) with aspirin. There have also been many cases where giving Ibuprofen to someone with Chickenpox has led to the development of a serious bacterial skin condition called Necrotising Fasciitis."

"Keeping your child’s nails short is always recommended to prevent sharp scratching and spreading Chickenpox to others. If a blister bursts while itching, wash your child’s hands carefully with soap and running water. As there is already vaccination for chickenpox, this could be done for those who have never had it and are not exposed to it." Dr. Costa said.

Meet the expert:

Having worked for many years in the NHS, mostly as Lead Clinician within an integrated Community Sexual Health Service, Dr Deborah Lee now works as a health and medical writer, with an emphasis on women's health, including medical content for Dr Fox pharmacy. She has published several books and remains passionate about all aspects of medicine and sexual health. After completing her Medical Degree at University of Southampton Medical School in 1986, Dr Lee trained as a GP and after a number of years specialised in Sexual & Reproductive Health (S&RH).

Dr José Costa is a senior consultant paediatrician, specialising in the latest research, medical guidance and insight on childhood food allergies, Rhinitis (Hay Fever), Eczema, Asthma, and associated conditions. With over 16 years of experience in Paediatrics and 12 years in Paediatric Allergy, Dr Costa is a member of the Royal College of Paediatrics and Child Health. He has also practiced as a senior medic in both the NHS and private sector, having led both the Paediatric Allergy Services at University Hospitals Coventry & Warwickshire and Sherwood Forest Hospitals NHS Foundation Trust.  As part of his own specialist Children’s Allergy Clinic, in Warwickshire, Dr Costa has become renowned for his leading expertise, supporting families affected by allergies across the UK, including the children of well-known public figures, celebrities and TV sporting personalities.

Mummy to a little girl, Adejumoke Ilori is Commercial Content Writer for Mother&Baby. With a BA hon in Creative Writing, she has worked for digital platforms, where she has empowered women from the inside and out, by sharing real life stories based on relationships, loving yourself and mummyhood.

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