Roseola infantum is an infection caused by a type of herpes virus. It typically affects babies and toddlers.

Other names for this health issue are sixth disease, exanthema subitum, or just “roseola.” Around 90% of roseola cases occur before 2 years of age.

This article summarizes how to identify roseola and how to tell the difference between this illness and measles. It also examines whether treatment is necessary.

Roseola usually affects toddlers and babies under 2 years old. They may also have or show:

  • general discomfort
  • irritability
  • an unwillingness to eat
  • diarrhea
  • a cough
  • swelling or redness around the eyes
  • ear pain
  • swollen glands

Roseola has a distinctive progression:

  1. A high fever develops, possibly suddenly, and may last for 3–5 days.
  2. A distinctive rash appears, usually on the torso, as the fever ends.
  3. The rash may progress to the neck, face, and limbs within 12–24 hours.
  4. The rash disappears after 1–2 days.

The roseola rash may look like small pink spots or bumps that can merge into patches.

In some babies, the rash is reddish, and it may turn a lighter color when a person applies pressure. There can sometimes be a paler “halo” around the rash area.

The roseola rash does not usually cause pain, itchiness, or any blistering. It usually starts on the trunk of the body and can sometimes progress to the neck, face, arms, and legs.

About two-thirds of roseola cases also occur with Nagayama spots. These can be ulcers or papules that appear at the back of the mouth.

Roseola results from infection with one of two main strains of the human herpesvirus (HHV): HHV-6 or HHV-7.

After infection, HHV-6 or HHV-7 attach to the salivary glands and brain tissue, remaining in the body after the baby or toddler recovers from roseola symptoms.

These viruses belong to the Herpesviridae DNA virus family, of which eight can infect humans.

The other six viruses are:

  • herpes simplex virus 1
  • herpes simplex virus 2
  • varicella-zoster virus
  • Epstein-Barr virus
  • cytomegalovirus
  • Kaposi’s sarcoma herpes virus.

Most herpes viruses, including those that cause roseola, transmit person-to-person through direct contact with someone who is infected.

Roseola and measles both cause rashes and are common during childhood. However, measles can also develop at any age, while roseola rarely affects adults. Find other important differences below.

Cause

Unlike roseola, which is caused by the HHV-6 or HHV-7 viruses, measles (or rubeola) results from the measles virus. People transmit it through respiratory droplets and close contact. When the virus enters the body, it suppresses the immune response, and it can do so for up to several years.

Rash appearance

Generally, a measles rash begins on the face and then moves downward. The rash takes 1-3 days to develop. Children with measles will also usually have a rash before a fever.

The roseola rash, on the other hand, tends to appear as the fever is diminishing or after it has passed, which usually takes 3–5 days. The rash tends to appear on the torso and may progress to the face and limbs.

Complications

Children with roseola usually recover with no need for treatment from a doctor.

However, a high fever can be a common symptom of roseola, and it causes febrile seizures in 10–15% of cases. This is the most common complication of the infection.

It is also worth noting that babies and toddlers with weakened immune systems tend to experience more severe symptoms of this infection.

Also, the virus can reactivate if the child’s immune system is suppressed. As a result, children with cancer or who have had a transplant are more at risk of reactivation than other children.

Also, HHV-6 infection has been associated with:

People with measles often recover with no complications. However, some people develop hearing loss or pneumonia, and measles can lead to inflammation of the brain, which can be life-threatening.

The risk of complications is higher in children and babies under 5.

Prevention

There is currently no vaccine for roseola. Measles, meanwhile, is a preventable illness with a very effective vaccine.

The vaccine is given in two doses: one when a baby is 12–15 months old, and one when they are 4–5 years old. This usually happens so that a child is vaccinated before they enter school.

In some cases, however, a child may need to get vaccinated on a different schedule. The Centers for Disease Control and Prevention (CDC) provide a more detailed vaccine schedule.

There is no specific treatment for roseola. Over-the-counter pain relief medication such as acetaminophen (Tylenol) or ibuprofen (Advil or Motrin) can usually control the fever. It is important to check the dosage carefully based on the child’s weight and be sure that it is appropriate for the baby or toddler.

Do not use aspirin to treat pain for roseola. It may cause Reye’s syndrome in children, which can be deadly.

It is important to let the baby rest and make sure that they receive plenty of fluids. It is important to follow good hygiene, such as by washing the hands frequently, to prevent the infection from spreading.

It is important to seek medical attention right away if a baby has a high fever, a persistent rash, or both.

If there are signs of a febrile seizure — a seizure brought on by a high fever — seek immediate care.

Signs of a febrile seizure include:

  • moaning
  • rolling eyes
  • vomiting or urinating
  • convulsing, shaking, or twitching
  • losing consciousness

A doctor can diagnose roseola by checking for symptoms and considering their medical history. They may also use a blood test to support the diagnosis.

Anyone with a compromised immune system who comes into contact with a child who has roseola should receive medical advice.

Roseola is an infection that typically affects babies and toddlers. It causes a high fever that lasts for 3–5 days, then a rash that starts on the trunk and can move to the rest of the body. The rash is very distinct, and it progresses in a characteristic pattern, starting from the torso.

There is no specific treatment or vaccine. Usually, roseola will resolve within about a week. An age-appropriate dosage of ibuprofen (Advil) or acetaminophen (Tylenol) can usually reduce the fever.