Roseola (sudden exanthema)


What is it about ?

Sudden exanthema, better known as roseola or sixth disease, is a common childhood disease. Its main characteristic is a sudden high fever (up to 40 ° C). After 3 to 5 days, the fever subsides as quickly as it rose and small pink spots appear on the face, in the neck, then on the trunk. Most of the time, the spots do not appear until the fever stops.

The disease is caused by a virus, the herpes virus type 6 (HHV-6). This is not the virus that causes classic herpes or a cold sore.
Usually, the disease is not serious and even goes unnoticed.

Where does it occur?

The disease mainly affects children aged 6 months to 2 years. It is almost never seen in children younger than 3 months or older than 3 years. Most children have had the disease before they are 2 years old.

How to recognize it?

The time between infection and the appearance of the first signs of disease (incubation period) varies from 5 to 15 days.

Roseola begins with a high fever, which can rise to 39 ° C or more and which can persist for 3 to 5 days. The fever subsides on its own.
In small children, it can cause convulsions (in 10 to 15% of cases). It is also sometimes the first sign of the disease, even before the fever is noticed.

After 3 to 5 days, when the fever subsides, the child develops a skin rash. Sometimes the rash starts a little before the temperature drops, sometimes it starts 1 day after the fever has completely subsided. Small red spots appear first behind the ears, then on the face and on the trunk.
The rash goes away on its own after a few hours or days.
The child may also have small red dots in the mouth.
Only a minority of children with HHV-6 infection develop this characteristic rash.

In most cases, the child is not very sick. He can sometimes be more difficult and eat less well, but very often the disease goes unnoticed.

A conjunctivitis may occur. In this case, the white of the eye becomes red and the eyelids may be swollen. There is nothing dangerous about it.

How is the diagnosis made?

The doctor will make the diagnosis based on the characteristic course of the disease and the rash.

During the physical examination, he will often also feel swollen glands in the neck and he will be able to notice the characteristic small red dots on the lining of the mouth and the palate.

Since the disease resolves on its own, no further examination is performed. The doctor will order a blood and urine test only in cases where he is in doubt of the diagnosis, such as when the fever and rash last unusually long.

What can you do ?

It is not necessary to take special measures for your child. He shouldn’t stay in bed if he doesn’t want to. He can go to the bath or shower as usual, even if he has a rash. Often, he will lack his appetite. It does not matter. However, make sure that your child drinks enough, especially if he has a fever.

You also don’t necessarily have to bring down the fever. This is a defense reaction against infection, which is harmless. However, if the child is overwhelmed by a fever or does not feel well, you can give him paracetamol. But this treatment will not necessarily prevent fever seizures.

Prevent your child from becoming dehydrated due to a fever. To find out if he is dehydrated, you can check to see if the eyes are still shining and the lining of the mouth is still wet. You can also lightly pinch the skin of the stomach for 10 seconds. If the fold on the skin is still visible 20 seconds after releasing your fingers, the child is probably dehydrated. Dehydration is also known when the baby’s fontanelles (the soft parts of the skull) are sagging.

Since almost all children have the infection before their second year of life, isolating infected children is unnecessary. Contamination often occurs even before symptoms appear. If the child feels well, he can therefore go to nursery or school normally.

Roseola is safe for pregnant women.

If your child is less than three months old, however, it is essential to seek immediate medical attention.

What can your doctor do?

There is no treatment for roseola.

In rare cases, infection with HHV-6 can lead to inflammation of the brain (encephalitis) in children. In this case, the doctor will refer you urgently to the hospital.

Want to know more?

Source

Foreign clinical practice guide ‘Exanthème subit’ (2000), updated on 04.08.2016 and adapted to the Belgian context on 02.06.2019 – ebpracticenet