Review the following clinical presentations of pediatric exanthems and pair each patient scenario with the most likely causative viral agent.
- An 8-month-old infant experiences 3 days of high fever (39.5°C) without a clear source. When the fever suddenly breaks, a diffuse blanching maculopapular rash immediately erupts on the trunk and spreads outward.Human herpesvirus 6
- A 6-year-old child develops bright red, coalescing erythema on both cheeks. Two days later, a lacy, reticular rash appears on the proximal extremities and trunk.Parvovirus B19
- A 4-year-old unimmunized boy has a prodrome of cough, coryza, and conjunctivitis. Tiny white papules on an erythematous base appear on the buccal mucosa, followed by a descending maculopapular rash.Measles virus
- A 15-year-old unimmunized adolescent presents with mild fever and prominent tender suboccipital lymphadenopathy. A fine pink rash begins on the face and spreads rapidly over the entire body within 24 hours.Rubella virus
Answer
The correct pairings are: the 8-month-old with rash after fever to Human herpesvirus 6; the 6-year-old with slapped cheeks to Parvovirus B19; the 4-year-old with Koplik spots to Measles virus; and the 15-year-old with suboccipital adenopathy to Rubella virus.
Each clinical presentation contains pathognomonic features linking it to a specific viral etiology. Recognizing the timing of fever relative to the rash (HHV-6), characteristic facial erythema (Parvovirus B19), specific mucosal enanthems like Koplik spots (Measles), and unique lymphadenopathy patterns (Rubella) are the keys to distinguishing these childhood infections.
Step-by-Step Solution
Key Concept
Differentiating classic pediatric viral exanthems based on prodromal symptoms, rash morphology, and sequence of onset.