Review Question - QID 210405

A 32-year-old man is brought to the emergency department by his wife for altered mental status. He was in his usual state of health until 3 days ago when he developed a headache and fever. Bright lights hurt his eyes. He is minimally responsive today. The patient is adopted and does not know his family history. He occasionally has a beer with dinner, and works as a landscaper. The patient’s temperature is 103°F (39.5°C), blood pressure is 131/78 mmHg, pulse is 84/min, and respirations are 14/min with an oxygen saturation of 98% on room air. Physical examination is notable for neck stiffness and a rash which is shown in Figure A noted by the patient a week or so ago. Which of the following is the most appropriate treatment?