A 32-year-old man from Tamil Nadu with borderline lepromatous leprosy (BL) presents with acute onset fever, painful nodules on the extensor surfaces, and tender subcutaneous nodules. He had completed 4 months of multidrug therapy (MDT). On examination, there are tender erythematous nodules on the shins and forearms, and he has mild hepatosplenomegaly. His lepromin test is strongly positive. What is the most likely diagnosis?