Match the following classic pediatric clinical presentations with their most likely causative viral pathogen.
- An infant presents with a generalized, rose-pink macular exanthem that appeared abruptly just after a continuous 72-hour period of elevated temperature normalized.Human herpesvirus 6
- A school-aged child develops prominent bilateral cheek erythema, followed days later by a reticulated, erythematous eruption on the proximal extremities that worsens with warm baths.Parvovirus B19
- An unvaccinated child exhibits a downward-spreading confluent exanthem accompanied by severe photophobia, coryza, and small white papules on the buccal mucosa.Measles virus
- An adolescent develops a faint pink, maculopapular eruption starting on the face and spreading downward, accompanied by prominent tender postauricular and suboccipital adenopathy.Rubella virus
Answer
The presentations match chronologically and morphologically to their respective pathogens: abrupt rash after fever resolution matches Human herpesvirus 6; slapped cheeks and lacy rash match Parvovirus B19; severe prodrome with Koplik spots matches Measles virus; and mild cephalocaudal rash with postauricular adenopathy matches Rubella virus.
Each pediatric viral exanthem possesses distinct chronologic and morphologic features. Human herpesvirus 6 uniquely causes a rash that appears only after the fever breaks. Parvovirus B19 is identified by its lacy, reticular pattern following slapped-cheek erythema. Measles is diagnosed by severe prodromal toxicity, the 3 Cs, and Koplik spots prior to the coalescing rash. Rubella is identified by a milder presentation with characteristic tender occipital and postauricular adenopathy.
Step-by-Step Solution
Key Concept
Differentiation of classic pediatric viral exanthems relies on the chronological relationship between fever and rash, distinct morphological patterns, and specific physical findings (e.g., Koplik spots, characteristic adenopathy).