Chickenpox (varicella)

Chickenpox (varicella) is very contagious. This viral infection most commonly affects children. Typical symptoms are an extremely itchy skin rash with red blisters and a slight fever. Chickenpox is much rarer today than in the past, as most children are now vaccinated against it.

If someone contracts chickenpox, they are contagious for one to two days before the rash becomes visible. Precautionary measures and good hygiene practices can help prevent the virus from spreading to other people.

While chickenpox is an unpleasant illness, it only rarely has serious consequences in otherwise healthy children. The infection can also be severe in newborn infants, adults, and people with a weakened immune system.

People who contract chickenpox initially feel generally unwell. The virus causes headache, muscle pain, and a high temperature. Next, the typical itchy skin rash appears, usually on the face and trunk of the body at first, and then on the scalp, arms, and legs.

In some cases, the genitals and mucous membranes are also affected. The main discomfort is caused by the extreme itching, which may also interfere with sleep. In adults with chickenpox, the rash may not develop or may not spread over the body as it usually does in children.

With chickenpox, fever lasts between 3 and 5 days but very rarely exceeds 39 degrees Celsius. The rash consists of small, red spots and bumps, which may develop into blisters. The blisters are filled with fluid that is initially clear, but later turns cloudy in appearance.

After a number of days, these dry out and form a crust (scab), which soon falls off. In most cases, the blisters clear up within 3 to 5 days. As the blisters on the skin are in different stages of development at any given time, their appearance is sometimes described as a “starry sky”. The number of blisters that develop varies widely from person to person.

Chickenpox is caused by the varicella-zoster virus. This belongs to the family of herpes viruses, which spread from person to person through droplet infection or direct contact.

All it takes to become infected is to breathe in tiny droplets of saliva that are released into the air when an infected person breathes out, coughs, sneezes, or speaks. The fluid from inside the blisters is also contagious. If they are scratched off or burst open, a “smear infection” may occur.

Almost any contact with someone who has chickenpox leads to infection. Generally, only people who have previously had chickenpox or who have been vaccinated against it are immune to infection.

Most chickenpox infections occur in children aged between 2 and 10. Adolescents and adults who have not had chickenpox as children and who have not received a vaccination can also contract the virus.

The Standing Committee on Vaccination in Germany (STIKO) at the Robert Koch Institute in Berlin has recommended vaccination against chickenpox since 2004. As most parents now follow the recommendation and have their children vaccinated, chickenpox cases are now much rarer in Germany than they were in the past.

Before 2004, around 750,000 children and adults became infected with chickenpox each year. In contrast, only 22,200 cases of chickenpox were recorded in Germany in 2017. Despite this, chickenpox remains one of the most common childhood illnesses.

After becoming infected, it usually takes around two weeks for the first symptoms to appear, although they can begin as early as one week after infection.

In other cases, the incubation period, i.e., the time between getting infected and the appearance of the first symptoms, can take up to three weeks.

Chickenpox in children usually clears up within a period of two weeks. Adults frequently experience a more severe infection than children. In adults, chickenpox can take longer to clear up and can be associated with more severe symptoms. The risk of developing complications is also higher.

Once a person has had chickenpox, they usually remain immune to the virus for the rest of their lives and are very unlikely to become infected again.

The STIKO recommends that the following groups should be vaccinated if they have not yet had chickenpox:

• children aged 11 months and older
• adolescents
• women trying for a baby
• people with certain diseases, such as severe neurodermatitis

The statutory health insurance providers cover the cost of chickenpox vaccination in Germany. Two injections of the vaccine are administered four to six weeks apart.

If an individual has never had chickenpox and is not vaccinated, they can still get the vaccine after coming into contact with someone who is infected. In this case, the vaccine must be given within five days of the contact to prevent infection or at least make the symptoms milder.

Pregnant women cannot be vaccinated. However, if they are at risk of becoming infected, they can be injected with antibodies that fight the virus. This is known as passive immunization, and is also possible for newborns if their mother becomes infected within a few days of the birth.

In rare cases, people who have received the chickenpox vaccine can still get infected. However, in most cases, the symptoms are milder and the risk of developing complications is also reduced.

Chickenpox has been classed as a notifiable disease in Germany since March 2013. This means that doctors must inform their local health authority if one of their patients is diagnosed with or even only suspected of having chickenpox.

More detailed information, for instance on how to avoid a chickenpox infection, is available at gesundheitsinformation.de.

Doctors can usually diagnose chickenpox based on the very typical skin rash it causes. A blood or blister test sample will only be taken and tested for the viruses if the illnesses is not progressing as normal.

An antibody blood test allows the doctor to determine whether the patient has previously had chickenpox and has therefore developed immunity. This type of test may be required for pregnant women, for example.

In most cases of chickenpox, it is only the symptoms that are treated. If the infection is severe or if the patient is at an increased risk of developing complications, the doctor may prescribe medication to combat the virus (antivirals).

Lotions, gels, or powders are often used to alleviate the itching and to dry out the blisters. These treatments usually contain zinc, tannins, menthol, or polidocanol. Sometimes, oral medication is recommended to alleviate the itching, for example, antihistamines. However, the effectiveness of these medicines for chickenpox has not yet been thoroughly investigated.

Symptoms like fever and aching limbs can be treated with anti-febrile pain-relieving medicines containing paracetamol as the active ingredient. Painkillers containing ibuprofen are not suitable for treating children with chickenpox.

Children and adolescents can only take medicines containing the active ingredient acetylsalicylic acid (ASA) if it has been prescribed by a doctor – and only as a last resort, because it can cause a rare but dangerous condition called Reye’s syndrome in children and adolescents.

As the itching can be extreme, it is often difficult for those with chickenpox to stop themselves from scratching the blisters. However, it is important to avoid scratching as far as possible – not only because the blister fluid is contagious, but because scars are left behind if the scabs are scratched off.

Keeping the fingernails short can help children to avoid scratching. Cotton mittens can be put on infants and small children to make it more difficult to scratch the blisters. In addition, wearing loose-fitting clothes made of smooth fabrics can help prevent further skin irritation.

With chickenpox, having a shower is generally better than taking a long bath because the skin doesn’t absorb as much water. After showering and washing, the skin should be patted dry very carefully.