Roseola (Sixth Disease) in Children

If your child's high fever of several days suddenly came down and pink-red spots appeared on the body just as you were thinking "they're better now," this picture may be sixth disease.

Sixth disease, known medically as roseola infantum (exanthem subitum), is a viral infection seen especially in babies and young children.

The most characteristic feature of the illness is that a high fever usually lasting 3 to 5 days comes down quickly and a rash then appears.

In most children the illness clears on its own. However, because a febrile seizure can occur in some children as a result of the high fever, the feverish period of the illness in particular needs to be watched carefully.

What Is Sixth Disease?

Sixth disease is a childhood infection caused mostly by Human Herpesvirus 6B (HHV-6B) and, more rarely, by Human Herpesvirus 7 (HHV-7).

The word "herpes" in its name can cause worry among families.

However, HHV-6 and HHV-7 are different viruses from the herpes simplex viruses associated with cold sores or genital herpes.

Sixth disease is seen particularly often in the first years of life.

At What Age Does Sixth Disease Occur?

Sixth disease is seen most often in children between 6 months and 2 years of age.

The reason for this is that antibodies passed from the mother provide a certain degree of protection in the first months of life, and as this protection decreases in the following months, the child comes across the virus.

Although it can also be seen in older children, the typical picture of sixth disease is above all an illness of infancy and early childhood.

How Does Sixth Disease Begin?

The illness usually shows itself with a high fever that starts suddenly.

The fever can reach 39-40°C, and sometimes higher, and usually lasts 3 to 5 days.

One of the striking features of sixth disease is that in some children the general condition can look better than the level of the fever would suggest, even though the fever is quite high.

Even so, the illness does not run the same course in every child.

The fever may be accompanied by symptoms such as:

• Irritability
• Poor appetite
• Mild runny nose
• Mild cough
• Enlarged lymph nodes in the neck or behind the ears
• Sometimes diarrhea

What Does the Rash of Sixth Disease Look Like?

The most characteristic finding of sixth disease is the rash that appears after the fever comes down.

The child usually has a high fever for 3 to 5 days. The fever then comes down quickly and the child begins to feel better.

It is right at this point that pink or red, small, flat or slightly raised spots may appear on the trunk.

The rash:

• May start first on the chest, the abdomen and the back
• May then spread to the neck, the arms, the legs and sometimes the face
• Is usually not itchy

It may fade on its own within a few hours to a few days.

The rash starting as the fever comes down is one of the most characteristic features suggesting sixth disease.

Is There a Rash in Every Case of Sixth Disease?

No.

The classic picture of "high fever → the fever coming down → a rash" may not be seen in every child who has an HHV-6 infection.

In some children the illness may run its course with a high fever only, and no clear rash may ever appear.

For this reason, the absence of a rash does not on its own rule out an HHV-6 infection.

How Does Sixth Disease Spread?

HHV-6 can spread particularly through close contact with saliva and respiratory secretions.

The virus is quite widespread in the community, and many people come across it during childhood.

Preventing transmission completely is not easy. Even so, washing hands regularly, avoiding shared cups and spoons, and paying attention to hygiene rules can help reduce the spread of infections.

How Long Is the Incubation Period of Sixth Disease?

There is usually a period of about 5 to 15 days between coming across the virus and the start of symptoms.

After this period, a high fever that begins suddenly usually appears.

Is Sixth Disease Dangerous?

In the great majority of healthy children, sixth disease is an infection that runs a mild course and clears on its own.

One of the most important problems of the illness is febrile seizures related to the high fever.

A febrile seizure can develop in some children, especially during the period when the fever is rising quickly.

Far more rarely, serious complications such as encephalitis or hepatitis have been reported. These are not the usual course of sixth disease.

Can Sixth Disease Cause a Febrile Seizure?

Yes, it can.

The HHV-6B infection that causes sixth disease is one of the infections associated with febrile seizures in young children.

However, not every child who has sixth disease has a febrile seizure.

If a child is having a seizure, emergency medical evaluation is needed, especially if it is a first seizure, if the seizure is prolonged, if it recurs or if the child does not return to their normal state afterward.

What Should Be Done If a Febrile Seizure Occurs?

A child having a seizure is a very worrying situation for a family.

During a seizure:

• The child should be laid on their side in a safe area
• Nothing should be put in their mouth
• No attempt should be made to give water or medicine
• No attempt should be made to forcibly stop their movements

How long the seizure lasts should be noted.

Emergency medical help should be sought, especially for a first seizure or a seizure lasting longer than 5 minutes.

How Is Sixth Disease Diagnosed?

In most children, sixth disease is diagnosed from the history of the illness and the examination findings.

A high fever coming down quickly after continuing for a few days, followed by the appearance of the characteristic rash, particularly supports the diagnosis.

In sixth disease that runs a typical course, a special blood test or PCR study for HHV-6 or HHV-7 is usually not necessary.

However, there is an important point:

Before the rash appears, sixth disease may run its course with a high fever only.

During this period, especially in young children, it may be necessary to evaluate whether a urinary tract infection or another infection lies behind the fever, according to the child's age and clinical condition.

For this reason, it is not correct to automatically treat a high fever of unknown cause as "sixth disease."

How Is Sixth Disease Treated?

Sixth disease is a viral infection, and in the great majority of healthy children no specific antiviral treatment is needed.

The main aim of treatment is to support the child's general condition.

During this period:

• Taking in enough fluid
• Rest

If the child is uncomfortable because of the fever, using fever reducers appropriate for their age and weight in line with the physician's advice

may be enough.

The rash usually fades on its own without needing any specific treatment.

Are Antibiotics Used in Sixth Disease?

No.

Because sixth disease is caused by viruses, antibiotics have no place in treating the illness.

An antibiotic should be used only if the child is separately found to have a bacterial infection that requires one.

Does the Rash of Sixth Disease Need a Cream or Ointment?

Usually no.

The rash of sixth disease is mostly not itchy and fades on its own within a short time.

For this reason, applying a cream or another medication to the rash is not necessary in most children.

Does the Rash Appearing Mean the Illness Has Gotten Worse?

On the contrary, in classic sixth disease the appearance of the rash usually coincides with the end of the feverish period.

That is why families may worry and ask, "The fever is gone but now the body has broken out — is the illness getting worse?"

In sixth disease, typically the fever comes down, the child's general condition improves, and the rash then appears.

However, if the child's general condition is getting worse while the fever is still present, or if the rash is purple-red and does not fade when pressed, this should not be considered the classic rash of sixth disease and the child should be evaluated.

Are Sixth Disease and Measles the Same Thing?

No.

Although both can run their course with fever and a rash, they are different illnesses caused by different viruses.

In sixth disease, the rash characteristically becomes apparent after the high fever comes down.

In measles, on the other hand, the fever and other symptoms of the illness may continue when the rash appears, and the clinical course of the illness is different.

Especially in a child who is unvaccinated or incompletely vaccinated, if there is fever and a rash, it is important for a physician to make the differential diagnosis.

Does Sixth Disease Come Back?

The classic picture of sixth disease appearing again in the same child is not a commonly expected situation.

After a primary infection with HHV-6, the virus can remain in the body in a latent state, as is a general feature of herpesviruses. However, in healthy children it is not expected to produce the classic picture of sixth disease over and over again.

When Should You See a Doctor for Sixth Disease?

Medical evaluation is needed particularly if:

• There is a high fever in a young baby
• The fever has been going on for a few days
• The child cannot take in enough fluid
• The amount of urine has clearly decreased
• The general condition is getting worse
• There is unusual sleepiness or a change in alertness
• The child is having difficulty breathing
• The child is having a seizure
• The rash looks purple or like bleeding into the skin and does not fade when pressed