A 9-month-old infant develops high fever for three days with no localizing signs, followed by defervescence and the sudden appearance of a rose-pink maculopapular rash on the trunk. The causative agent is:

• A Parvovirus B19
• B Rubella virus
• C Measles virus
• D Human herpesvirus 6 ✓

Explanation

Roseola infantum (exanthem subitum) presents with three to four days of high fever in an infant, followed by abrupt defervescence and a transient maculopapular rash on the trunk. It is caused by human herpesvirus 6, with HHV-7 accounting for a minority of cases. Rubella rash appears concurrently with low-grade fever, measles rash erupts as fever peaks, and parvovirus D19 causes erythema infectiosum with slapped-cheek appearance in older children.

Reference: Nelson Textbook of Pediatrics, 22nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.