Toxic epidermal necrolysis : the worst form of drug skin reaction ; involves greater than 30% of total body surface. Nicolsky sign is what distinguish it from stevens_johnsohn syndrome wher the skin slips off with gentle tug. Rx: admission to burn unit with fluids ressussitation and IVIG
I saw a patient who had this (might have been SJS). He was en ex-biker with most of his upper body and arms covered in tattoos. They came out looking nearly as fresh as the day they were made! He made a full recovery but was admitted for nearly three months.