Toxic epidermal necrolysis (TEN) is a disorder characterized by the sudden onset of widespread erythema and tenderness of the skin with rapid progression to desquamation of sheets of epidermis, resembling scalding. Although the clinical picture is similar in many instances, toxic epidermal necrolysis is subdivided into two main clinicopathologic types, those due to staphylococcal infections, and the nonstaphylococcal variant. It occurs as the result of a number of causes, including specific exfoliative toxin-producing staphylococci, drugs, vaccines, and the graft vs. host reaction. Differentiation of these types is important, both for therapeutic and prognostic reasons.