A 32-year-old man from rural Maharashtra, diagnosed with lepromatous leprosy 8 months ago, presents with acute onset of painful nodules and plaques on his face, trunk, and extremities over the past 3 days. He also reports fever (38.5°C), malaise, and tender nodules. His treatment compliance has been excellent. On examination, the existing leprotic lesions appear inflamed. Slit-skin smear shows numerous acid-fast bacilli. What is the most likely diagnosis?