Chickenpox

What is it? 

Chickenpox is a viral infection caused by the Herpes varicella zoster virus. It's spread in droplets inhaled into the respiratory tract. Complications are rare but serious, and can  occur in previously healthy children. 

Who's affected? 

Chickenpox tends to affect  children under ten. Most children have had the infection by this age. In  older children and adults, chickenpox  can be more severe. 

It's more common in late winter and spring. Children who are immunosuppressed (for example, on steroids) are particularly vulnerable to complications, as are newborn babies who may catch the infection  from their mother in late pregnancy. 

What are the symptoms? 

The incubation period (from exposure  to onset of symptoms) is 14 to 24 days. The initial symptoms are mild  fever and headaches. Younger children may seem generally grouchy. 

These are followed within hours by the appearance of a typical rash. Crops of red spots appear, which quickly develop central fluid-filled  blisters that are intensely itchy. After a couple of days these scab over  and dry up. 

The rash mostly affects the trunk, but may appear anywhere  on the body, including the  scalp and the mouth. 

In about one in ten cases symptoms are so minimal the infection goes unnoticed. 

Complications of the infection are uncommon but include viral pneumonia, secondary bacterial infection and encephalitis. 

What's the treatment? 

Talk to your doctor if you're unsure of the diagnosis  or if your child seems particularly unwell, has a cough, headache, if the skin  is particularly inflamed or infected, or there are other worrying symptoms. 

For young babies or children with immunity problems, always seek medical advice. 

Give pain-relieving syrup  and plenty of fluids. Calamine lotion and antihistamine medicines may relieve the itching. 

Keep your child's hands clean and their fingernails short. Try  to discourage them from scratching the spots, as they can scar. 

The spots may be infectious until they've fully scabbed over,  but no child should need to be kept from school for more than five days. 

In severe cases, antiviral treatment may be recommended. 

Most children recover without long-term  problems. But  children at high risk who are exposed  to chickenpox must be treated with immunoglobulin injections to prevent  the infection, or antiviral drugs to treat it. 

There is also a vaccine that can be given to prevent chickenpox. 

After infection  the virus lies dormant in the body but can emerge later to  cause shingles.