MRCP2-0996

A 70-year-old man with non-Hodgkin’s lymphoma, currently in remission, was admitted with pneumonia. He was given tazocin intravenous (IV). Three days later, he developed an erythematous maculopapular rash all over his body.

The following day, a trainee nurse urgently calls you to the ward as she noticed that his skin was ‘peeling off’ as she was turning him over. Upon arrival, you see him in a pool of fluid, with large areas of skin loss and other regions of dusky skin necrosis. His conjunctivae are red, and his mouth has multiple blisters.

What is the most probable underlying pathophysiology of this mucocutaneous drug reaction?