Stevens Johnson Syndrome/Toxic Epidermal Necrolysis Syndrome Support Network

A type of hypersensitivity (allergic) reaction that occurs in response to medications, infections, or illness. In Stevens-Johnson syndrome, the systemic symptoms are severe and the lesions are extensive, involving multiple body areas (especially the mucous membranes). Toxic epidermal necrolysis (TEN syndrome, or Lyell's syndrome) involves multiple large blisters (bullae) that coalesce, followed by sloughing of all or most of the skin and mucous membranes.