Review Question - QID 213525

A 24-year-old man presents to the emergency department with a lesion on his genitals. He states that he noticed it yesterday and it has not improved on its own. The patient is generally healthy and works with livestock on a farm. He is not currently taking any medications and does not use recreational drugs. His temperature is 98.5°F (36.9°C), blood pressure is 122/80 mmHg, pulse is 75/min, respirations are 11/min, and oxygen saturation is 97% on room air. Physical exam is notable for the finding in Figure A. Palpation of the lesion does not elicit any symptoms. The patient is given a medication and discharged. He returns to the emergency department subsequently and states that since taking the medications he has felt ill and has diffuse pain in his muscles and joints as well as a headache. His temperature is 101°F (38.3°C). Which of the following is the best next step in management?