Chickenpox

What is chickenpox?

Chickenpox is a viral infection that causes an itchy skin rash with blisters that burst and scab over. 

Chickenpox most commonly affects children. It is usually mild but can cause serious, even life-threatening complications in some people.

What causes chickenpox?

Chickenpox is caused by the varicella-zoster virus. It is highly contagious, meaning it spreads easily to other people. You can catch chickenpox from someone who has it if you haven’t had chickenpox before or had the chickenpox vaccine.

It is possible to catch chickenpox if you’ve had the vaccine or had chickenpox before, but this is rare.

How is chickenpox spread?

Chickenpox can be spread by:

• Touching the rash or fluid from the blisters of someone who has chickenpox.
• Breathing in droplets from the air when an infected person coughs or sneezes

On average, chickenpox symptoms appear ten to 21 days after exposure to the virus. You are contagious (can spread the virus to others) from two days before the chickenpox rash develops until your blisters have all dried and crusted over.

Chickenpox symptoms

Chickenpox symptoms occur in several stages.

• Early symptoms of chickenpox — the first symptoms of chickenpox often occur a few days before the rash develops and may include:
  • Feeling generally unwell
  • Fever
  • Body aches
  • Headache
  • Loss of appetite
• Chickenpox rash — a rash normally develops a day or two after early symptoms begin. It starts as itchy, raised, bumps (papules) that may:
  
  • Start on your face, chest, and back and spread to the rest of your body including your hands, feet, eyes, ears, mouth, and genital area
  • Be pink, red, the same colour as your skin or darker.
  • Be harder to see on black or brown skin
• Fluid-filled blisters —the papules will form fluid-filled blisters (vesicles). These burst after about a day and leak fluid
• Spots crust over — the spots begin to dry out and scab over

Chickenpox symptoms usually last for between four and seven days.

Chickenpox complications

In healthy children, chickenpox is usually a mild disease that goes away without treatment, but in rare cases, chickenpox can lead to serious or even life-threatening complications. Some people have a higher risk of developing complications including:

• Newborn babies
• Babies under a year of age whose mothers have not had chickenpox or the chickenpox vaccine
• Pregnant women
• People with a weakened immune system

Complications from chickenpox include:

• Dehydration
• Bacterial infections of the skin, soft tissue, bones, joints and blood
• Pneumonia (inflammation of the lungs)
• Encephalitis (swelling of the brain)
• Reye’s syndrome
• Liver problems
• Blood clotting disorders
• Toxic shock syndrome

When to see a consultant for chickenpox

Chickenpox is normally a mild illness that clears up on its own without treatment. In rare cases, chickenpox can lead to complications that may be serious and require hospitalisation.

If you are worried about your/your child’s symptoms, make an appointment with your consultant. Chickenpox is highly contagious, so call the hospital first to let them know you or your child may have chickenpox.

Make an appointment to see your consultant if:

• You think your newborn baby has chickenpox
• You are worried about your child’s symptoms
• Your child has chickenpox and is showing signs of dehydration 
• Your/ your child’s symptoms suddenly get worse
• The skin around your/your child’s chickenpox blisters is red, hot and painful
• You are pregnant, have not had chickenpox before (or are unsure), and have had contact with someone with chickenpox
• You have a weakened immune system and have had contact with someone with chickenpox

How is chickenpox diagnosed?

Chickenpox can usually be diagnosed by looking at your rash. A test for chickenpox can be done if necessary.

How is chickenpox treated?

Chickenpox usually clears up on its own. Some things you can do at home to help with symptoms of chickenpox include:

Self-care for chickenpox

• Rest 
• Drink plenty of fluids
• Avoid scratching as it can lead to permanent scarring. If your child is scratching, keep their fingernails short and put socks or mittens on their hands
• Wear loose, breathable fabrics
• Apply cool compresses to your rash or bathe in cool water and gently pat your skin dry
• Eat a soft diet if you have blisters in your mouth

Over-the-counter medications

Your pharmacist can advise you on over-the-counter medicines to help relieve the symptoms of chickenpox. These may include:

• Paracetamol — to relieve pain and bring down a fever
• Antihistamines — to relieve itching
• Lotions and gels to soothe the itching
• Do not take ibuprofen unless advised by your consultant as it may cause serious skin infections
• Children under 16 should not take aspirin

Prescription medications

Prescription medications are not usually necessary for chickenpox, but if you are an adult with chickenpox, or have a high risk of developing complications, your consultant may prescribe an antiviral medication.

Can chickenpox be prevented?

The best way to prevent chickenpox is to have the chickenpox vaccine. In the UK, the chickenpox vaccine is available on the NHS if you have close contact with someone at high risk of developing complications from chickenpox.

The chickenpox vaccine is over 90% effective. In the United States, cases of chickenpox have fallen by 97% since the introduction of the vaccine.

You can also choose to pay for the vaccine privately.

Preventing the spread of chickenpox

To reduce the risk of spreading chickenpox to others:

• Keep your child off school or nursery until all their spots have crusted over
• Adults with chickenpox should stay off work until all their spots have crusted over
• Avoid contact with others as much as possible until all your spots have crusted over. Take particular care to avoid contact with people at high risk of complications from chickenpox including:
  • Newborn babies
  • Pregnant women
  • Anyone with a weakened immune system

Summary

Chickenpox is a common viral infection that usually affects children. It is normally mild and clears up within a week or two without treatment. In some cases, serious complications from chickenpox can develop, particularly in high-risk groups such as newborn babies, pregnant women and people with weakened immune. An effective vaccine for chickenpox is available.