A 48-year-old man presents with a 2-month history of low-grade fevers, weight loss, and diffuse muscle aches. He also reports tingling and burning pain in his right foot and hand. On examination, there are tender subcutaneous nodules on his trunk, livedo reticularis on his lower extremities, and decreased sensation in a stocking-glove distribution. Laboratory studies reveal elevated ESR and CRP, serum creatinine of 2.1 mg/dL (baseline 1.0), and normal chest radiograph. Hepatitis B surface antigen is positive. Which of the following is the most likely diagnosis?