Review Question - QID 109699

A 62-year-old man presents to the emergency department with skin lesions. He felt itchy recently, then noticed skin lesions that broke out prompting him to come to the emergency department. He recently went camping and hiking in the woods. The patient drinks 1-2 beers per day and smokes 1 pack of cigarettes per day. He is currently sexually active with multiple partners and does not use condoms. The patient was discharged 1 week ago for pneumonia which was treated with azithromycin; however, he feels that his symptoms may be returning. His temperature is 99.5°F (37.5°C), blood pressure is 157/78 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 98% on room air. Physical exam reveals the findings in Figure A on the patient's arm. The skin lesions are thick and do not break when pressure is applied. Which of the following most appropriately describes the most likely diagnosis?