Chickenpox is a common childhood ailment, with over 80% of people in the UK, US, and Japan becoming infected at some point in their lives.¹ It’s characterised by an itchy, spotty rash that causes blisters. It typically resolves itself within a week or two, without the need to see a GP. However, children who are immunocompromised may experience severe illness and require antiviral and antibiotic medication. A vaccine is available for those in close contact with the immunocompromised to help reduce the risk of potential, life-threatening complications.

What is chickenpox?

Chickenpox is a viral infection caused by varicella-zoster. In the UK, it is extremely common amongst children below the age of 10, particularly between March and May, as vaccination is not part of the standard NHS immunisation programme. After being infected with the virus, most people are generally protected for the rest of their lives. However, some people can become reinfected, although they may be asymptomatic during the second infection.²

Your child may catch the virus by being in the same room with an infected person, or by touching a surface which has been exposed to fluid from a viral blister.² People with chickenpox are infectious from 2 days before any spots begin to appear until the spots have scabbed over – about a week in total. 

Symptoms

The main chickenpox symptom is an itchy, spotty rash across the body. There are generally three stages of this infection, although new spots can develop while others are in more advanced stages.

Image showing chickenpox across the torso and arms.

Image showing chickenpox spots on day five of infection on a person with a darker skin tone.

Stage 1: small spots appear

1-3 weeks after your child catches chickenpox, spots can appear anywhere on the body, including inside the mouth and around the groin. The rash can become itchy 12-14 hours after it has begun. Depending on the colour of the skin, the spots can be pink, red, darker than, or the same colour as the surrounding skin. Chickenpox spots may be more difficult to see on darker skin tones.

Stage 2: blistering

After a few days, you will notice the spots becoming filled with fluid to form blisters. These are quite itchy and can burst

Stage 3: scabbing

Towards the end of this infection, the spots will begin to form scabs, while others can leak fluid. Scabbing usually takes place 5 days after the initial infection

Other symptoms

Your child may also experience these symptoms before or after the appearance of the chickenpox rash:

• Feeling unwell
• Body aches and pains
• Fever
• Lack of appetite
• Sore throat²
• Dry cough³

Treatment

Treatment typically involves managing the symptoms of chickenpox:

• Children should refrain from attending school or nursery until most of their spots have formed scabs
• Ensure your child stays hydrated to help them recover. If they’re unable to take in fluids, try giving them ice popsicles
• Dress your child in loose clothes to prevent further discomfort and irritation
• Cut your child’s nails and place socks on their hands at night to prevent them from scratching their blisters. This will help prevent them from developing a bacterial infection and/or scars
• Make sure your child is bathing or showering in cool water. Pat the skin dry as opposed to rubbing
• You can try using over-the-counter cooling creams, gels and calamine lotions to help soothe your child’s itch
• Your pharmacist may be able to provide you with antihistamines to help your child deal with their itchy rash
• Paracetamol can help with any pain and fever your child is experiencing. Depending on your child’s age, you may prefer to give this to them in syrup form

Here are some things to avoid when treating your child:

• Don’t give them ibuprofen unless advised to by a doctor, as this can cause some major skin infections
• Don’t give aspirin to children under 16, as this can result in Reye’s syndrome
• Avoid going near anyone who may be immunocompromised, including newborn babies or people who are pregnant. People exposed to chickenpox in this group can develop serious complications which can be fatal 

Complications

Although complications in healthy children are less common than in healthy adults, they can still occur. These include:

• Dehydration
• Blood clotting issues
• Liver disease
• Pneumonia
• Other bacterial infections
• Reye’s syndrome 

If you suspect your child has developed a bacterial infection, let your GP know. They will be able to prescribe antibiotics for your child to take and may advise your child to be hospitalised. 

When to see a GP

Call 111 or book an emergency GP appointment immediately if:

• You think your newborn baby has chickenpox
• Your child has a weakened immune system and has come in contact with someone infected with chickenpox
• Your child has chickenpox and has become dehydrated
• Your child’s chickenpox symptoms suddenly become worse
• The skin around chickenpox blisters is painful, hot, and red. This may be a sign of a bacterial infection. Keep in mind that redness and irritation may be more difficult to see on darker skin

Your GP may prescribe your child acyclovir, which significantly reduces symptoms if taken within 24 hours of the rash beginning.² This medication stops the virus from spreading further by preventing its cells from copying their DNA, inhibiting their survival.⁴ Your child may experience the following side effects on this medication: 

• Headaches
• Nausea and vomiting
• Dizziness

You should let your GP know if your child’s symptoms worsen while taking the medicine, or do not improve after taking the full course. If your child’s chickenpox is resistant to acyclovir, they may require treatment with foscarnet, which is more aggressive.⁴

Diagnosis

If your child requires a GP appointment, diagnosis will usually be done by assessing your child’s skin. If further confirmation is needed, fluid from the blister may be used to perform a PCR test.^4,5

Prevention

There are two NHS vaccines available if you or your child are in close contact with someone who is immunocompromised. This is because people with a weakened immune system are not able to get the vaccine due to the risks of complications. However, by ensuring those around them are vaccinated, their chances of becoming very sick can be significantly reduced. If your child is over 9 months old and has not yet had chickenpox, they may be eligible for one of these vaccines. Not all GP clinics offer this service, so make sure to check with your practice. The vaccine is given in two doses, about a month or two apart. After this, children will have 98% protection against the virus, and no booster doses are required

The chickenpox vaccine contains a weakened version of the varicella-zoster virus, which helps the body to produce antibodies to fight off the infection. Once your body comes across the virus in the wild, memory immune cells recognise the virus as varicella-zoster. This enables your child to produce the necessary antibodies much faster. This means that even if they become infected with chickenpox, your child will have few symptoms, if any. Side effects of taking this vaccine include:

• A rash developing within a month from when the injection was given 
• Swelling or pain at the injection site
• Fever

Shingles

Shingles can occur in anyone who has previously been infected with chickenpox. After a person has recovered from chickenpox, the virus remains in their nervous system for the rest of their lives and can reactivate.⁴ If your immune system is weakened at any point in your life, you may develop shingles due to the varicella-zoster present in your body. This can occur due to stress, or treatments which naturally suppress your immune system, such as chemotherapy. Although more common in adults, children can also develop shingles. Shingles isn’t contagious, and you can’t catch it from someone with chickenpox either. However, you can catch chickenpox from someone who has shingles. 

If you think your child may have shingles, you should call 111 or book an emergency GP appointment. You can also get help from your local pharmacist. Your practitioner can provide medications to prevent long-term problems and speed up recovery. Symptoms of shingles include:

• Headache
• A painful or tingling sensation in a specific area
• Feeling ill
• A sore rash that shows up a few days after initial symptoms. This tends to be on the chest and stomach, although it can be anywhere across the body. Occasionally, shingles can present without a rash

Image of a shingles rash.

Image of a shingles rash on an elbow.

Summary

Chickenpox is a common viral infection in children, caused by the varicella-zoster virus. It's highly contagious and characterised by an itchy, spotty rash that results in stages of spots, blisters, and scabs. Most cases resolve within one to two weeks without medical intervention, although children with weakened immune systems may require antiviral and antibiotic treatments. The virus is spread through direct contact with infected fluids or air droplets. Treatment at home is usually enough, but immunocompromised infants may require antiviral medications. Those who have had chickenpox may develop shingles later in life.