Which of the following is a key feature of roseola?

A key feature of roseola, also known as sixth disease, is indeed the presentation of a high fever followed by the development of a rash. This condition is most commonly caused by human herpesvirus 6 (HHV-6) and typically affects children under the age of 2.

The clinical course of roseola usually begins with a sudden onset of a high fever that can last for several days. This fever can be quite high, sometimes reaching up to 104°F (40°C). Following the resolution of the fever, a characteristic rash appears. The rash usually starts on the trunk and then spreads to the extremities. It consists of rose-pink macules or spots that blanch upon pressure.

Recognizing this sequence of symptoms is crucial in diagnosing roseola and differentiating it from other viral exanthems, which may not follow this particular pattern. The presence of a high fever preceding the rash is a classic hallmark that practitioners look for as they evaluate young children presenting with febrile illnesses.