Roseola Infantum

(Exanthem Subitum; Pseudorubella)

ByBrenda L. Tesini, MD, University of Rochester School of Medicine and Dentistry
Reviewed/Revised Jun 2023
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Roseola infantum is a contagious viral infection of infants or very young children that causes a high fever followed by a rash.

  • Roseola infantum is caused by infection with human herpesvirus-6.

  • Typical symptoms include high fever that begins suddenly and sometimes a rash that develops after the temperature returns to normal.

  • The diagnosis is based on symptoms and the age of the child.

  • Treatment is aimed at relieving symptoms.

Roseola infantum occurs throughout the year, most often in the spring and fall. Sometimes minor local outbreaks occur.

The usual cause of roseola infantum is herpesvirus-6, one of the many human herpesviruses.

Most children who develop roseola infantum are between 6 months and 3 years of age.

Roseola infantum is spread by breathing in small droplets that have been breathed out by an infected person. Droplets also can be breathed in when an infected person talks, coughs, or sneezes. If the droplets land on surfaces and children touch those surfaces and then their nose or mouth, they can become infected. The infection is often spread by close contact with a person who has the infection but does not have any symptoms, such as a family member. It is not known when people are contagious.

A person who has had roseola infantum develops immunity and usually cannot contract it again.

Symptoms of Roseola Infantum

Roseola infantum symptoms begin about 5 to 15 days after infection. A fever of 103 to 105° F (about 39.5 to 40.5° C) begins abruptly and lasts for 3 to 5 days. In 5 to 15% of children, seizures occur as a result of high fever, particularly because the fever begins and rises quickly. Despite the high fever, the child is usually alert and active.

A few children have a mild runny nose, sore throat, or an upset stomach.

The lymph nodes at the back of the head, the sides of the neck, and behind the ears may be enlarged.

The fever usually decreases rapidly on the fourth day.

Rash Caused by Roseola Infantum
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This photo shows the flat, red rash caused by roseola infantum.
SCOTT CAMAZINE/SCIENCE PHOTO LIBRARY

About 30% of children with roseola infantum develop a rash within a few hours to, at most, a day after the temperature falls. The rash is red and flat. It occurs mostly on the chest and abdomen and less extensively on the face, arms, and legs. The rash is not itchy and may last from a few hours to 2 days.

Diagnosis of Roseola Infantum

  • A doctor's evaluation

A doctor suspects roseola infantum when typical symptoms (particularly development of a rash after a high fever goes away) appear in a child aged 6 months to 3 years.

Tests are rarely done, but the diagnosis of roseola infantum can be confirmed with blood tests.

Treatment of Roseola Infantum

  • Acetaminophen or ibuprofen for fever to provide comfort

The seizures and rash do not require any specific treatment, but because they are frightening, most parents bring their child to the doctor for evaluation.

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