Q. A 45-year-old man presents to the clinic with a sudden onset of fever, headache, and a non-pruritic maculopapular rash that began on the wrists and ankles and has spread to the trunk in the past 5 days. The patient reports recent outdoor activities, including hiking and camping in a wooded area. His temperature is 101.5°F (38.6°C), pulse is 110 beats per minute, blood pressure is 120/70 mmHg, and respiratory rate is 14 per minute. On physical examination, blanching erythematous macules are noted on wrists, ankles, and abdomen. Few petechiae and purpura are noted on the lower extremities. Lab investigations show platelets: 148,000/mm3. What is the most appropriate next step in his management?