The Fever Pattern of Roseola in Infants

Exanthema subitum, also known as roseola infantum, is a common acute exanthematous disease in infants and young children, primarily caused by human herpesvirus types 6 and 7. The initial symptom of exanthema subitum is usually a sudden high fever, which typically follows a two-phase pattern:

1. The incubation period, lasting approximately 5 to 15 days, during which the child suddenly develops a high fever, with body temperature rapidly rising to 39°C to 40°C or even higher. This high fever may last for about 4 days and may be accompanied by symptoms such as diarrhea, runny nose, and cough. The child's temperature may temporarily decrease after taking antipyretic medication, but fever may recur once the medication's effect wears off.

2. Around the fourth day after the onset of illness, the fever suddenly subsides, and rose-colored maculopapular rashes begin to appear on the child's body, which is the typical symptom of exanthema subitum. The rash appears as pale red maculopapular lesions, varying in size, with indistinct borders and no significant pruritus. Under normal circumstances, the rash gradually fades within 2 to 3 days without leaving any marks.

Although exanthema subitum is usually self-limiting, meaning the disease resolves on its own within a certain period, close monitoring of the child's condition is still necessary during treatment, ensuring timely hydration to prevent dehydration, and seeking medical attention when necessary.