Merck Manual

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Roseola Infantum

(Exanthem Subitum; Pseudorubella)


Brenda L. Tesini

, MD, University of Rochester School of Medicine and Dentistry

Reviewed/Revised Jun 2023
Topic Resources

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.

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.

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

Fever is treated with acetaminophen or ibuprofen.

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.

If the disease is severe in children with a weakened immune system, doctors may treat them with the antiviral medication foscarnet or ganciclovir.

Drugs Mentioned In This Article

Generic Name Select Brand Names
7T Gummy ES, Acephen, Aceta, Actamin, Adult Pain Relief, Anacin Aspirin Free, Aphen, Apra, Children's Acetaminophen, Children's Pain & Fever , Children's Pain Relief, Comtrex Sore Throat Relief, ED-APAP, ElixSure Fever/Pain, Feverall, Genapap, Genebs, Goody's Back & Body Pain, Infantaire, Infants' Acetaminophen, LIQUID PAIN RELIEF, Little Fevers, Little Remedies Infant Fever + Pain Reliever, Mapap, Mapap Arthritis Pain, Mapap Infants, Mapap Junior, M-PAP, Nortemp, Ofirmev, Pain & Fever , Pain and Fever , PAIN RELIEF , PAIN RELIEF Extra Strength, Panadol, PediaCare Children's Fever Reducer/Pain Reliever, PediaCare Children's Smooth Metls Fever Reducer/Pain Reliever, PediaCare Infant's Fever Reducer/Pain Reliever, Pediaphen, PHARBETOL, Plus PHARMA, Q-Pap, Q-Pap Extra Strength, Silapap, Triaminic Fever Reducer and Pain Reliever, Triaminic Infant Fever Reducer and Pain Reliever, Tylenol, Tylenol 8 Hour, Tylenol 8 Hour Arthritis Pain, Tylenol 8 Hour Muscle Aches & Pain, Tylenol Arthritis Pain, Tylenol Children's, Tylenol Children's Pain+Fever, Tylenol CrushableTablet, Tylenol Extra Strength, Tylenol Infants', Tylenol Infants Pain + Fever, Tylenol Junior Strength, Tylenol Pain + Fever, Tylenol Regular Strength, Tylenol Sore Throat, XS No Aspirin, XS Pain Reliever
Advil, Advil Children's, Advil Children's Fever, Advil Infants', Advil Junior Strength, Advil Migraine, Caldolor, Children's Ibuprofen, ElixSure IB, Genpril , Ibren , IBU, Midol, Midol Cramps and Body Aches, Motrin, Motrin Children's, Motrin IB, Motrin Infants', Motrin Junior Strength, Motrin Migraine Pain, PediaCare Children's Pain Reliever/Fever Reducer IB, PediaCare Infants' Pain Reliever/Fever Reducer IB, Samson-8
Cytovene, Vitrasert, Zirgan
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