What is Chickenpox? Symptoms, Advice and Treatment

Chickenpox is often easily recognised by its characteristic rash of small blisters. It is usually a mild and short-lived illness in children. Adults are at greater risk of severe chickenpox, and chickenpox in pregnancy poses certain risks.

There is an antiviral drug that can be used to decrease the severity and duration of a chickenpox attack in certain severe cases and under special circumstances such as in immune suppressed individuals. A vaccine for chickenpox is now commercially available. Chickenpox occurs worldwide as a childhood disease, which lasts four to five days and has the features of fever and a widespread rash of small blisters (vesicles) usually distributed on the chest, back and face with few blisters evident on the arms and legs.

Sometimes chickenpox can be more severe, with internal organs affected, such as the lungs and liver. An individual can only ever have one episode of chickenpox in their lifetime; once that person has recovered, they have life-long immunity to chickenpox. However, the virus that causes chickenpox belongs to the herpes virus family and like other members of this family, after recovery from the initial infection, the virus never actually leaves the host but ‘hides out’ in a latent state, not causing any illness, in certain nerve cells. This latent virus can be reactivated by a variety of different factors like stress, malnutrition and old age. The reactivated virus will cause illness, but in another form, different to the first infection. In the case of chickenpox the reactivation of the virus many years after a chickenpox attack causes shingles. Shingles is a band of painful blisters confined to one area of skin.  

Causes of chickenpox

Chickenpox is the illness that occurs when a person is first infected with the varicella-zoster virus, VZV, also known as human herpes virus type III. During the first (primary) infection, the virus is able to spread throughout the body – evident from the distribution of the rash over the whole body. Like its relative the Herpes simplex virus, the varicella-zoster virus persists in a person for the rest of their life. The virus becomes dormant in nerve centres in the spine. Chickenpox can occur in anyone who has not had the illness before. Shingles can only occur in someone who has had chickenpox before.

Chickenpox is highly contagious

The varicella-zoster virus is present in the throat secretions of a person just before or just after they develop the chickenpox rash. These secretions can reach another person as airborne droplets. The skin blisters of chickenpox and shingles also contain infectious viruses, which can reach the nose or mouth of another person, for example via fingers. Face-to-face exposure to someone with early chickenpox will put you at risk of infection. Even spending some time in the same room as a person with early chickenpox will put you at risk. The highest risk is associated with living in the same household as a person with chickenpox, and nine out of 10 people who have not had chickenpox before will contract the disease under these circumstances.

Symptoms of chickenpox

A mild headache, moderate fever and feeling unwell usually starts a day or so before the rash appears. In adults these preliminary symptoms can be more severe, with flu-like muscle pains. The rash initially appears as pinkish bumps of a few millimetres across, usually somewhere on the trunk (chest and abdomen). Within hours the bumps become itchy blisters containing a clear fluid (vesicles). The vesicles quite rapidly break down and crust (scab), but a new crop of vesicles appears just as the previous crop starts to crust. Typically 250 to 500 vesicles will form. In chickenpox the rash is most dense on the trunk with fewer vesicles on the face and limbs. Vesicles on the scalp may be accompanied by swollen lymph glands at the back of the neck. Along with the skin vesicles, vesicles can occur in the mouth and throat, under the eyelids and in the genital and anal openings. On these wet surfaces the vesicles tend to break down into ulcers and can be quite painful. One consequence of this is that swallowing may be difficult. Vesicles usually stop appearing by the fifth day of the rash, and most vesicles will be crusted by the sixth day.

Possible complications with chickenpox

While chickenpox is usually a mild illness in children, there are a number of possible complications: 

  • Because the rash is very itchy and children cannot help scratching, the most common complication is infection of vesicles by bacteria; this is known as secondary infection. With secondary infection the skin will redden and the vesicle sites will produce pus. In more severe cases the infection penetrates the tissues under the infected skin, causing swelling. While the chickenpox rash does not cause skin scarring, secondary skin infection can leave scars. A rising temperature can be a warning sign of serious secondary bacterial infection that has entered the bloodstream.

  • A different type of serious complication (haemorrhagic chickenpox) reveals itself by bleeding into the vesicle sites.

  • Chickenpox pneumonia is a serious complication that occurs when vesicles form in the lungs, and becomes evident by shortness of breath and a cough.

  • Chickenpox encephalitis complicates about one in 1,000 cases of chickenpox. It tends to occur toward the end of the illness. A common way in which children are affected is by loss of sense of balance, so that they develop a staggering walk. This is often associated with involuntary movements of the eyes. Other signs of encephalitis are personality change, irritability or drowsiness, which in severe cases will progress to loss of consciousness. 

Self-help tips for itching

  • Luke-warm baths

  • Cold compresses

  • Camomile lotion

  • Loose cotton clothing

  • Encourage children to have regular drinks. If necessary, administer analgesics to relieve pain on swallowing.

This information has been reproduced with kind permission of Zahra Publishing, publishers of Easy Health.