Necrotizing Fasciitis — Skin Necrosis + Crepitus

A 42-year-old man with poorly controlled diabetes presents to the emergency department with a 6-hour history of severe pain and swelling in his left groin and scrotum. On examination, the skin appears only mildly erythematous with minimal visible inflammation, yet the patient is in extreme distress and reports excruciating pain. The feature marked **C** in the diagram — pain out of proportion to skin findings — is the earliest clinical red flag that should immediately raise suspicion for necrotizing fasciitis. Which of the following best explains why this disproportionate pain occurs in necrotizing fasciitis?