Definition of Roseola:

Roseola is an acute disease of infants and young children in which a high fever and skin rash occur.

Causes, incidence, and risk factors:

The disease is common in children ages 3 months to 4 years, and most common in those ages 6 months to 1 year. It is caused by a virus called human herpesvirus 6 (HHV-6), although similar syndromes are possible with other viruses.

Roseola occurs throughout the year. The time between becoming infected and the beginning of symptoms (incubation period) is 5 to 15 days. A fever lasting 3 (sometimes up to 7) days generally comes before the rash appears. The fever may be as high as 105 degrees Fahrenheit.

Roseola begins with a high fever that generally responds well to acetaminophen (Tylenol). Between the 2nd and 4th day of illness, the fever falls dramatically, and a rash appears (often as the fever falls) on the trunk and spreads to the limbs, neck, and face. The rash lasts from a few hours to 2 days.