About Chickenpox (varicella)

Reviewed by Dr Jeni Worden, GP

What is chickenpox?

Chickenpox is a very contagious viral infection that usually runs its course without any problems in childhood.

Chickenpox is a highly contagious illness that's common in children. It causes an itching skin rash with blisters.

The disease is caused by the varicella-zoster virus and usually runs its course without problems.

How do you catch chickenpox?

The viral infection is transferred from one person to another through direct contact with the broken chickenpox blisters and through airborne droplets.

The infectious period lasts from about three days before the rash appears until all the blisters have formed scabs.

The incubation period between being infected with chickenpox until the disease breaks out and symptoms appear is 10 to 20 days.

What are the symptoms of chickenpox?

• A rash that usually begins on the body and face and later often spreads to the scalp and limbs.
• It may also spread to the mucous membranes, especially in the mouth and on the genitals.
• The rash is often itchy.
• It begins as small red spots, which develop into blisters in a couple of hours.
• After one or two days, the blisters turn into scabs.
• New blisters may appear after three to six days.
• The number of blisters differs greatly from one person to another.
• The infected person may run a temperature.
• These symptoms are mild in young children.
• Chickenpox lasts 7 to 10 days in children and longer in adults.
• Adults can feel very ill and take longer to recover. They are also more likely than children to suffer complications.

Who is at risk of complications?

• Pregnant women who have not had chickenpox.
• People with a weak immune system, such as those with acute or chronic leukaemia or HIV.
• Patients taking medicine to suppress their immune system, such as long-term oral corticosteroids.

Those in the at-risk group who are exposed to the varicella-zoster virus can be given an injection of varicella-zoster-immunoglobin to boost their immunity.

Vaccination against chickenpox is also available.

How does the doctor make a diagnosis?

The diagnosis is made by observing the symptoms and the typical appearance of the rash.

How is chickenpox treated?

• The treatment mostly consists of easing the symptoms.
• Remember that an infected person will be contagious until new blisters have stopped appearing and until all the blisters have scabs. They should stay at home while they are infectious.
• Avoid scratching the blisters because of the risk of infection.
• Cut the nails short or make the patient wear gloves.
• Pay attention to personal hygiene.
• If your child is in pain or has a fever you can give them a mild painkiller, such as paracetamol (eg Calpol) or ibuprofen (eg Nurofen for children). Follow the dosage instructions provided in the leaflet.
• Calamine lotion can help to relieve the itching.
• Keep the patient in cold surroundings because heat and sweat may make the itching worse.
• In attacks of chickenpox where the itching is so serious that the child's sleep is totally disturbed, antihistamine medicines with a heavily sedative effect can be used. Antihistamines are medicines for allergic reactions, motion sickness or insomnia.
• In serious cases of chickenpox in people with a weak immune system, aciclovir (eg Zovirax tablets/suspension), which works specifically against chickenpox, can be used.

Which complications might arise?

• Bacteria may infect the blisters.
• Occasionally scars may remain at the site of the blisters.
• Conjunctivitis.
• Pneumonia.
• In very rare cases, chickenpox can result in complications, such as meningitis, encephalitis, inflammation of the heart (myocarditis) or Reye's syndrome.

Future prospects

Once a person has had chickenpox, they will have immunity to the disease for the rest of their life. However, the virus may return later in life as shingles.

A person who has active shingles can infect others with chickenpox, but cannot give shingles to someone else.

Read more: http://www.netdoctor.co.uk/diseases/facts/chickenpox.htm#ixzz2JJF66IY2 
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