Chickenpox is classically thought of as an infection of childhood; however, it can also affect adults who have not previously been infected by the virus. Adults tend to suffer a more severe illness than children. It is particularly dangerous for pregnant women, newborns and people with impaired functioning of the immune system (such as HIV/AIDS patients). Chickenpox is caused by the varicella zoster virus, a virus related to herpes zoster. It is highly contagious and children should be kept home from school and kindergarten whilst infected.
Initially, the symptoms of chickenpox may be mistaken for a flu-like illness until the characteristic rash develops. These early symptoms tend to be more common in adults than in children; some children may break out in a rash with no warning signs. Signs and symptoms to watch for include:
- Discomfort and irritability
- Sore throat
- Loss of appetite
- General feeling of being unwell (malaise)
- Itchiness of the skin
- Rash: the rash in chickenpox is a vesicular rash, where small fluid-filled blisters develop on the skin. The surrounding patches of skin are typically red and inflamed
- Ulcers may also form on mucous membranes, such as those that line the mouth. Ulceration of the oral cavity and tonsils may occur 2-3 days before the rash develops
The varicella virus is transmitted by air-borne droplets. These are spread when the infected person coughs or sneezes. The virus may also be spread by directly touching or coming into contact with the infected blisters. The virus is highly contagious and the person is infectious for around 2 days before the rash develops – the individual may not feel any symptoms at this time. Once the rash has developed, the individual is contagious until all of the blisters have formed scabs, a process which generally takes about 5 to 7 days. Once every last blister has formed a scab, the child can return to school. It can take up to 16 days to develop the rash after initial contact and infection with the virus – this period is called the incubation period. Whilst the affected person is contagious, they should avoid people who are on chemotherapy or other treatments which affect the functioning of the immune system. This is because this group of people are particularly vulnerable to infection, and the consequences of chickenpox in this group are more severe.
The rash caused by varicella is described as being a vesicular rash, which means that tiny blisters form on the skin. Typically, the rash starts on the torso, then affects the head, face and neck and then appears on the arms and legs last. In the earliest stages, the rash may resemble small pimples, but then develop to become larger, fluid-filled blisters. The blisters may also become filled with pus; if this occurs, the lesions are termed pustules. After about 5 days, the blisters or pustules form crusts, and once all lesions have reached this stage, the virus is no longer contagious. The crusts become scabs, and it can take 16 or so days for the scabs to heal over completely.
Treatment & Prevention
The best means of preventing chickenpox is to ensure that your child receives the varicella vaccination. The vaccine is quite effective, and if vaccinated, there is a very high probability that they won’t get chickenpox if they come in contact with another infected child. Pregnant women are also strongly advised to have the chickenpox vaccine, especially if they were not infected with chickenpox as a child. Being infected with chickenpox during pregnancy can have some serious effects, therefore, vaccination is the best option.
There is no specific treatment for varicella – the infection is viral and antibiotics will be of no use. Paracetamol can help to reduce pain, fever, discomfort and a sore throat. Under no circumstances should you use aspirin if you are affected by chickenpox; especially children under 16, as there is a risk of developing a serious condition, called Reye’s syndrome.
Although very difficult, it is also important to try not to scratch the rash, as scratching increases the likelihood of scars developing and may increase the likelihood of developing a secondary infection. Some basic, natural measures which help to relieve the itch can include keeping your skin cool, taking a bath (adding bicarbonate soda or oatmeal bath products may also provide relief). Another popular option is calamine lotion, which can be applied to the skin and may provide relief from itch. Applying special dressings, called hydrogel dressings, can relieve the itching and, importantly, act as a barrier to stop scratching and hence prevent the likelihood of scars developing. Another over-the-counter method which may help to relieve the itch is antihistamines; however, check with your doctor before giving these to young children.
Although chickenpox is usually a mild, self-limiting illness in children, there can be serious complications associated with the infection. The serious complications are quite rare. Some of the possible complications of chickenpox include:
- Scarring: occasionally, people who have been infected with chickenpox are left with scars where the blisters were. These are called pockmarks. Pockmarks are round, pit-like scars and tend to be more commonly a complication of chickenpox in adulthood than childhood.
- Secondary bacterial infection: this is one of the most common complications associated with chickenpox. Scratching the rash can cause the skin to break and provides an opportunity for the entry of bacteria into the wound, which can then go on to cause an infection. The surrounding skin becomes more inflamed, and these secondary infections can be quite painful. These infections can be treated with appropriate antibiotic therapy.
- Cellulitis: cellulitis is a severe bacterial infection that can occur as a complication of chickenpox. The bacteria infect the skin and subcutaneous tissues, and the bacteria enter through damaged skin. The skin is acutely inflamed and is very hot, swollen and tender to touch. There is also commonly a discharge of pus from the skin. As cellulitis can spread very quickly, rapid treatment is necessary. Cellulitis is often treated in hospital with the administration of intravenous antibiotics
- Otitis Media: this is a complication particularly seen in children. Otitis media is an infection of the middle ear cavity that is often spread from the throat via the Eustachian tube
- Pneumonia: this complication tends to be seen more often in adults than in children and can be fatal. It is also caused by the varicella virus and produces wheezing and tachypnoea (rapid breathing rate). It usually occurs 3-4 days after the onset of the rash
- Encephalitis – the varicella virus can infect the brain, leading to inflammation. This complication is rare
- Cerebellar ataxia – sometimes, the virus may infect the cerebellum, an area of the brain responsible for the control of balance and co-ordination. The person will appear clumsy and will have difficulty walking
- Bleeding disorders – these are also a very rare complication. Bleeding disorders associated with chickenpox may be fatal
Chickenpox is not a common occurrence during pregnancy, as the majority of pregnant women are immune through prior exposure or vaccination. However, in the rare instances it does occur, there are important complications. The risk to the unborn child is greatest if the infection occurs in the first 20 weeks of pregnancy – infection after 20 weeks is less likely to produce complications. Some of the complications that can occur include:
- Hepatitis, encephalitis and pneumonia in the mother
- In the first 20 weeks of pregnancy, the foetus may be affected by scarring of the skin, small limbs, and eye and neurological problems
- Infection between weeks 20-36 may mean that the child may be affected by shingles in the first few years of life
- In the final four weeks of pregnancy, the newborn may suffer from chickenpox
Although the complications of chickenpox can be serious, they are also very rare. Due to vaccination, chickenpox is becoming less common in the community.
If you are concerned or have any other questions about chickenpox contact your local doctor, who will arrange for you to see a dermatologist. Contact us today.