Roseola, also known as "roseola infantum" or "exanthem subitum," is a viral infection that is characterized primarily by a high fever and a rash.
Human herpesvirus type 6 (HHV6) and, sometimes, human herpesvirus type 7 (HHV7) cause roseola. Both are members of the herpesvirus family of viruses.
Almost all children are infected during early childhood with HHV6 and HHV7, but only about one-third of children develop signs of roseola. The peak age for developing roseola is 6 to 15 months of age. More than 95% of cases occur in children younger than 3 years of age.
HHV6 and HHV7 are transmitted from person-to-person by direct contact or by contaminated secretions of the nose and the mouth. These viruses are spread through the blood throughout the body, which causes the rash.
The majority of children with roseola develop a characteristic illness with a very high fever (from 100F to 103F) for approximately three days, which is followed by the onset of a rash the day that the fever resolves. In contrast to what is usually expected with such a high fever, most children, during the fever, behave quite normally and continue with their usual play activities. Some infants may become irritable and have a decreased appetite. In classic cases, the rash typically appears within 24 hours after the fever resolves and then fades over one to three days; however, only approximately 25% of infected children may actually develop the rash.
Roseola is diagnosed primarily on the characteristically high fever followed by the development of the rash once the fever resolves. Unfortunately, this makes it very difficult to diagnose roseola during the course of the fever because, typically, there are no other symptoms.
There is a blood test that is available, but, usually, this is not used for diagnosis because either the illness has resolved completely after a few days, or the diagnosis can be made by the physician with some certainty because of the characteristic high fever followed by the rash.
There is no specific treatment for roseola. Antibiotics are not helpful because a virus causes roseola. Viruses cannot be treated with antibiotics. The disease is usually mild with complete recovery. Fever should be treated with acetaminophen or ibuprofen.
The major complication of roseola in children is the development of febrile seizures. During the time of the high fever, especially early in the infection, children may have seizures that are caused by the very high fever. Febrile seizures occur in 2% to 3% of all children, and usually are a problem between 6 months and 3 to 4 years of age. Many cases of febrile seizures that occur only once in a child are probably due to roseola.
A vaccine for roseola is not available. There is very little information on how to prevent roseola; however, outbreaks are uncommon. The spread of roseola can be prevented by minimizing exposure to children who have symptoms of the disease, and by good handwashing after exposure to the disease.
Research is being conducted on the transmission of human herpesvirus 6 and to characterize how the virus causes roseola.
About the Authors
Hal Jenson, M.D.
Dr. Jenson graduated from George Washington University School of Medicine in Washington, DC,
He also completed a residency in pediatrics at the Rainbow Babies and Children's Hospital of Case Western Reserve University in Cleveland, Ohio, and a fellowship in pediatric infectious diseases and epidemiology at Yale University School of Medicine.
Dr. Jenson has an active research program on the biology of Epstein-Barr virus and other human and non-human primate herpes viruses.
He is active in the general pediatric and infectious diseases teaching and clinical activities of his Department and Division, is a co-editor of Nelson Textbook of Pediatrics and of Pediatric Infectious Diseases: Principles and Practice, and authors the book Pocket Guide to Vaccination and Prophylaxis.
Charles T. Leach, M.D.
Dr. Leach received his medical degree at the University of Utah School of Medicine and completed his pediatrics residency as well as a fellowship in pediatric infectious diseases at UCLA.
He is currently Associate Professor and Director of Research in the Department of Pediatrics at the University of Texas Health Science Center at San Antonio.
Dr. Leach conducts scientific research in the areas of herpes virus infections, pediatric AIDS, and infectious diseases among residents of the Texas-Mexico border.
Copyright 2012 Hal B. Jenson, M.D., and Charles T. Leach, M.D., All Rights Reserved
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