Review Question - QID 213733

A 67-year-old man presents to his primary care physician with burning pain in his right hand. He states that it has been going on for years and has been gradually worsening during this time frame. He has tried taking acetaminophen and ibuprofen for the pain, but these have not improved his symptoms. The patient has a past medical history of diabetes and a 52 pack-year smoking history. His temperature is 99.0°F (37.2°C), blood pressure is 177/100 mmHg, pulse is 87/min, respirations are 18/min, and oxygen saturation is 95% on room air. Physical exam is notable for red and tender nodules in a linear pattern along his right upper extremity. Physical exam is notable for the finding in Figure A. Which of the following is the most likely etiology of this patient's symptoms?