6)
A 3-year-old girl is brought to the emergency department after her parents witnessed a 30-second episode of "shaking of her arms and legs." She is sleepy but responds to the clinician. She has no significant past medical history. Her examination is notable for a temperature of 103.1 F (39.5 C), oropharyngeal erythema, bilateral anterior cervical lymphadenopathy, and a palpable spleen tip. What is the next step in evaluating this child's condition?