Review Question - QID 214849

A 22-year-old woman presents to her primary care physician for a rash affecting her trunk over the last 3 days. She recently returned from a 2-week trip to Puerto Rico and did not have this rash prior to her travels. She denies any sick contacts, and the rash is neither pruritic nor painful. She has been wearing sunscreen daily during her trip and has a medical history of asthma, for which she takes an albuterol inhaler. Her temperature is 98.6°F (37.0°C), blood pressure is 110/70 mmHg, pulse is 65/min, and respirations are 14/min. Physical examination is remarkable for skin lesions shown in Figure A. Which of the following is the most appropriate next step in evaluating this patient's rash?