Question

An 18-month-old presents with a rash faint but covering the face, trunk, and extremities. Prior to getting the rash, the child had a 103F temperature "for a few days" that "all of a sudden went away". The most likely diagnosis is:

1) hand-foot-and-mouth disease
2) erythema infectiosum
3) roseola infantum
4) scarlet fever

Answer 1

Roseola infantum is the most likely diagnosis for the child with the described symptoms of high fever followed by a spreading rash that does not cause discomfort.

Step-by-step explanation:

The most likely diagnosis for an 18-month-old child with a history of a high fever that resolved, followed by a diffuse, faint rash covering the face, trunk, and extremities is roseola infantum. This condition, also known as exanthem subitum, is generally preceded by a high fever, which then subsides and is followed by the sudden appearance of a rash. Roseola is typically caused by human herpesvirus-6 (HHV-6) and sometimes by HHV-7. The rash in roseola starts on the trunk and then may spread to the neck, arms, and sometimes to the face and legs. This progression aligns with the symptoms presented by the child. The rash does not cause discomfort and usually resolves within a week after the onset of fever.