Painful, Indurated Nodules with Purple Discoloration

Painful, Indurated Nodules with Purple Discoloration

A 53-year-old man presented to the emergency department with a 1-month history of relapsing fevers, dyspnea, and rapidly progressive skin lesions. Physical examination revealed painful, indurated nodules with surrounding purple discoloration on his back, trunk, and limbs.

What is the most likely diagnosis?