roseola
Pronunciation: rose-ee-OH-la
A common viral illness in infants characterized by high fever followed by a distinctive pink maculopapular rash as fever subsides.
Full Definition
Roseola, also known as exanthem subitum or sixth disease, is a viral infection caused primarily by human herpesvirus 6 (HHV-6), with some cases due to HHV-7. The condition predominantly affects children between 6 months and 2 years of age and follows a characteristic biphasic pattern. The illness begins with sudden onset of high fever (often 39-40°C) lasting 3-5 days, during which the child may appear well despite the fever. As the fever breaks, a distinctive rose-colored, blanching maculopapular rash appears on the trunk and spreads to the neck, arms, and legs, typically lasting 1-2 days. The rash's appearance concurrent with fever resolution is pathognomonic for roseola. Febrile seizures may occur due to the high fever, but the overall prognosis is excellent.
Usage
Usage note: Emphasize the temporal relationship between fever resolution and rash appearance for accurate diagnosis.
In Context
- "The appearance of the characteristic rash as the fever resolved confirmed the diagnosis of roseola." — pediatric infectious disease consultation
- "Roseola should be considered in febrile infants who appear well despite high temperatures." — emergency medicine teaching rounds