What is a primary feature of Roseola infantum?

The primary feature of Roseola infantum, also known as sixth disease, is indeed the high fever that typically lasts for 3 to 4 days. This fever can reach temperatures as high as 103°F to 105°F and is often the first and most prominent symptom noticed in affected children.

Following the resolution of the fever, a characteristic rash usually appears, which distinguishes Roseola from other febrile illnesses. The rash is typically rose-colored and can last for several days. The pattern of a high fever preceding the rash is key in diagnosing this condition, making it critical for healthcare providers to recognize this sequence, as it can help in distinguishing Roseola from other childhood illnesses that may present with fever and rash simultaneously.

In contrast, the other options do not accurately describe the typical features of Roseola. A rash appearing before the fever, chronic cough, and persistent diarrhea are not associated with Roseola infantum, reinforcing that a high, sustained fever lasting several days is the hallmark manifestation of this viral infection.