Roseola

What is roseola?

Roseola is also known as roseola infantum, exanthem subitum, sixth disease and three-day rash. The disease is most common in those aged 6 months to 3 years. It is rare in adults, probably because childhood infection gives lifelong immunity to most people. It is usually caused by a virus called human herpesvirus type 6 (HHV-6). It may also be caused by human herpesvirus type 7 (HHV-7).

Children infected with the roseola virus will typically develop the following symptoms:

• A high temperature (fever) suddenly develops. The child can be flushed, irritable, and unwell with the fever. The temperature can be as high as 40°C. The fever typically lasts 3-4 days and then drops quickly back to normal.

• A rash usually appears when the fever subsides, when the child is getting better. Small pink spots appear. They usually start on the body and then spread to the arms and legs. The rash does not usually develop on the face. The rash is not itchy or painful and does not blister. The rash usually lasts for about 1-2 days, but sometimes fades within hours.

• Some children get similar spots in their mouth (on the soft palate and the uvula).

• A sore throat, cough and runny nose may develop and the child may go off their food.

• Some glands in the neck may swell.

Roseola is often diagnosed when the child is getting better. At first the high fever may cause concern to parents and doctors if it is not clear what is causing it. Other more serious illnesses may need to be ruled out. The sudden drop in fever and the appearance of the typical rash are reassuring. This indicates that the fever has been caused by the roseola virus and nothing more serious.

Roseola

© Emiliano Burzagli, Public domain, via Wikimedia Commons

Roseola is contagious. The spread of the virus is from person to person via saliva. The time from infection to symptoms appearing (incubation period) is 9 to 15 days. The chid is probably infectious during the whole period of the disease and maybe even before the high temperature (fever) appears.

There is no treatment that kills the virus. Treatment aims to keep the child as comfortable as possible until the illness goes.

Dealing with a high temperature (fever)

A fever can make a child feel uncomfortable and irritable. There are things that you can do that may bring the temperature down and make your child feel more comfortable.

You can give paracetamol or ibuprofen to lower a temperature and help ease headaches, and aches and pains. You can buy paracetamol and ibuprofen in liquid form, or as melt-in-the-mouth tablets, for children. Both these medicines come in various brand names. The dose for each age is shown on the medicine packet.

Do not use more than advised on the packet or bottle. Do not use ibuprofen in children in whom attacks of asthma have been triggered by ibuprofen in the past.

Keep your child cool. Take extra layers of clothes off your child if the room is normal room temperature. Use light cotton clothes or bedding. Open windows or use a fan in the room where appropriate. Do not cold-sponge a child who has a fever. This used to be popular but it is now not advised.

This is because the blood vessels under the skin become narrower (constrict) if the water is too cold. This reduces heat loss, and can trap heat in deeper parts of the body. The child may then get worse. Many children also find cold-sponging uncomfortable.

Give lots to drink. This helps to prevent a lack of fluid in the body (dehydration). You might find that a child is more willing to have a good drink if they are not so irritable. So, if they are not keen to drink, it may help to give some paracetamol first. Then, try to give the child a drink 30 minutes or so later when their temperature is likely to have come down.

Encourage your child to have plenty to drink if they have a fever. Signs of dehydration include:

• A dry mouth.

• No tears

• Sunken eyes.

• Drowsiness.

• Generally becoming more unwell.

• Passing less urine or having fewer wet nappies.

Seek medical help if you suspect that your child is becoming dehydrated.

Sometimes the high temperature (fever) can cause a fit (also known as a febrile convulsion or febrile seizure). This can be alarming but is usually not serious. Other reported complications are very rare. Full recovery is normally expected. People who have a weakened immune system (immunocompromised) may suffer from more serious complications such as encephalitis, myocarditis and hepatitis.

Once a person has had this condition then they will be immune from having it again.