Chickenpox

Introduction

Chickenpox (varicella) is a highly contagious viral disease. Chickenpox - also known in Switzerland as "wild chickenpox" or "chicken pox" - is usually transmitted by droplet infection; preschool children are most commonly affected. In addition to general symptoms such as headaches or aching limbs, varicella is characterised by a blistering rash, sometimes with severe itching. Winter and spring are the classic chickenpox seasons.

The incubation period - the time between infection and the appearance of the first symptoms - is usually two weeks. Once chickenpox has broken out, it takes around ten days for the blisters to heal and the infected person can no longer infect other people. The disease is often more severe in adults than in children and can lead to pneumonia or brain inflammation, for example.

In the case of chickenpox in children, only the symptoms are usually treated by taking medication and applying lotions to relieve the itching. The varicella blisters should not be scratched open, as this promotes infection with bacteria. A chickenpox vaccination prevents the disease.

Symptoms

Chickenpox causes general symptoms such as headaches, aching limbs and a slight fever. Far more unpleasant, however, are the spots and blisters, which are often extremely itchy: These are small, reddish, round to oval and spread over the entire body as well as the mucous membranes. The rash occurs in varying degrees of intensity and different stages at the same time (so-called "starry sky").

As the disease progresses, the patches develop into nodules and blisters filled with fluid. These burst, crust over and heal. The symptoms of chickenpox usually last five to ten days. Infected children develop antibodies against the pathogens - normally they are then immune to chickenpox for life.

Course

The incubation period - the time between infection and the first symptoms - is usually two weeks. Once chickenpox has broken out, it takes around ten days for the blisters to heal. Sick people are already contagious for one to two days before the rash or other symptoms appear. The risk of infection continues until all the blisters have completely healed.

In most cases, chickenpox in children has no complications; the varicella heals without consequences. Blisters that burst or are scratched open during the course of the disease can easily become infected with bacteria. Such an infection prolongs the healing process and can lead to permanent scars. Those affected should not use ointments to heal wounds, but lotions can be used. As the ointment is relatively airtight, the wound underneath is a good breeding ground for bacteria.

Adults are less likely to become infected with varicella, as most people have had the disease in childhood and are therefore immune to the virus as adults. This means that a person usually only contracts chickenpox once in their lifetime. However, if an adult is infected with varicella, the disease is often more severe than in children.

The feeling of illness is usually stronger, more blisters form and serious complications such as pneumonia or encephalitis can occur. In rare cases, however, severe courses are also possible in children.

Like other adults, pregnant women who have not had chickenpox or who have not been vaccinated against chickenpox (i.e. are not immune) can also become infected with chickenpox. A chickenpox infection in the first half of pregnancy can lead to severe brain damage in the unborn child in up to two per cent of cases. In addition, there is a risk of severe complications for the pregnant woman herself (especially pneumonia); if chickenpox is contracted around the time of birth, the newborn baby may also suffer severe complications. For this reason, non-immune pregnant women should avoid contact with people suffering from varicella as far as possible and be vaccinated against chickenpox after pregnancy. Pregnant women who have had chickenpox, on the other hand, are protected from contracting the disease.

Although a person usually only contracts varicella once in a lifetime, anyone who has had chickenpox can contract the disease again in the course of their life: the virus can be reactivated in the form of shingles.

Causes

In the case of chickenpox, certain viruses - the so-called varicella-zoster viruses - are the cause of the disease. The viruses are transmitted by droplet or smear infection, for example through coughing or sneezing or through direct contact with the infectious contents of a blister. Varicella zoster viruses belong to the group of herpes viruses.

The virus is also the causative agent of the possible secondary disease shingles. During initial infection, the virus colonises the skin and mucous membranes as chickenpox; however, it also reaches nerve cell clusters, where the virus remains "dormant" for the rest of its life. Certain factors reactivate the virus and subsequently trigger shingles.

Chickenpox is very contagious. Close contact with infected persons in particular is a risk for transmission - whether by sharing a room or other close contact.

Diagnosis

In most cases of chickenpox, doctors can make a diagnosis quickly and without further examinations due to the characteristic skin rash. In the case of varicella, telemedical treatment by telephone or video is therefore very possible and particularly useful, as chickenpox is a very contagious viral disease and further infection through contact with other people can be avoided. As part of telemedical treatment, those affected can send a photo of their rash and thus support the doctor's diagnostic process.

If further medical clarification is required, the varicella-zoster virus can also be detected directly in the contents of the blisters. Doctors also have the option of analysing the affected person's blood for viruses or antibodies produced by the body against the virus. However, laboratory tests are only necessary in individual cases - for example, if the mother is pregnant, if the blisters reappear after seven days or if there are hardly any blisters in the affected child.

Treatment

The treatment of chickenpox in healthy children is normally limited to measures that alleviate the symptoms. The actual viral infection is not treated. Those affected should not scratch the blisters, as this promotes infection with bacteria. Parents should therefore cut the fingernails of children with chickenpox short. It is also advisable not to bathe until the blisters have crusted over, but only to shower. The main aim is to reduce the itching and prevent bacterial infections. The following remedies alleviate the symptoms of chickenpox:

• Antipruritic preparations in the form of medication or lotions
• Careful skincare
• Wear airy clothing (tight clothing increases itching)
• Cooling baths for 10 minutes

In case of fever: paracetamol

Patients aged 16 and over should be treated with an antiviral medication within 24 hours of the onset of the rash if possible. This can reduce the risk of a severe course.

Prevention

There is a chickenpox vaccination against varicella (also known as varicella vaccination), which prevents the disease. The Federal Office of Public Health recommends that everyone between the ages of 11 and 40 who has not yet had chickenpox should be vaccinated. This applies in particular to women who wish to have children. It should also be noted that a woman should avoid pregnancy for the following 28 days after vaccination. Vaccination is also advisable for people with certain risk factors - for example, HIV infection, leukaemia or severe neurodermatitis. Apart from vaccination, it is difficult to protect yourself from infection as the viruses are highly infectious.

In general, it helps to avoid contact with people who are ill. Sick people should stay at home if possible and only meet people who have already had chickenpox and are therefore immune. Women who wish to have children, who have not yet had chickenpox and are therefore not resistant, should always take precautions against contracting the disease.

In cases where contact with infected persons has nevertheless occurred, it may be advisable for those affected to be vaccinated prophylactically (post-exposure prophylaxis):

• Non-immune pregnant women (have not had chickenpox, no chickenpox vaccination)
• Immunocompromised persons
• All adults aged 16 and over
• Non-immune children with chronic skin or lung disease

These people should seek medical advice immediately, as vaccination can prevent or alleviate a severe case of chickenpox.