Review Question - QID 216685

A 37-year-old rancher presents to the local clinic with a 3-day history of a rash on his arm. He says that he suffered a number of scrapes while clearing thorn bushes about 1 week ago and did not think much of it at the time. A few days later, he began to notice an itchy, raised lesion near the site of the cuts that filled with liquid. About 1 day later, the lesion popped and began to turn black. He has no significant past medical history and does not use any substances other than an occasional beer with dinner. His temperature is 99.0°F (37.2°C), blood pressure is 135/75 mmHg, pulse is 78/min, respirations are 14/min, and O2 saturation is 99%. The lesion is shown in Figure A. A diagnosis is made and he is started on a medication. Less than a week later, the patient returns to clinic complaining of a painful rash on his face and forearms bilaterally. Which of the following is the most likely cause of this patient's new symptoms?