Roseola infantum is caused by human herpesvirus infection, primarily characterized by high fever for three to five days. After the fever subsides, a rash appears. The rash, consisting of small, dense red maculopapules, is primarily located on the trunk and face, with fewer occurrences on the limbs. The entire rash appears in one day and gradually fades the following day. The rash does not cause itching, so there is generally no need for special anti-itch medications. The rash usually fades gradually the day after it appears and leaves no scars once it has cleared. The appearance of the rash after the fever subsides indicates that the herpesvirus infection is nearing recovery, requiring no special treatment.