Toxic epidermal necrolysis (TEN) is a symptom complex characterized by a devastating skin disorder, erosive involvement of two or more mucous membranes, and severe constitutional symptoms. The disorder shares features with erythema multiforme and is thought to be an expression of the syndrome. Although a wide range of etiologic factors have been incriminated in TEN, only a few cases have provided convincing evidence of a direct causal link. Most cases of TEN have been associated with drug administration.