A 9-month-old infant has high fever (40°C) for 3 days with no focal signs. As the fever subsides, a blanching maculopapular rash appears on the trunk. What is the most likely causative agent?
- A Human herpesvirus 6 ✓
- B Parvovirus B19
- C Group A Streptococcus
- D Measles virus
Correct answer: A. Human herpesvirus 6
Explanation
Roseola infantum (exanthem subitum) is caused by human herpesvirus 6. It is characterized by high fever for 3-4 days followed by a rash that appears as the fever resolves. Parvovirus B19 causes erythema infectiosum with a slapped cheek rash. Group A Streptococcus causes scarlet fever. Measles presents with cough, coryza, conjunctivitis, and Koplik spots.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.