Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are two forms of a life-threatening skin condition, in which cell death causes the epidermis to separate from the dermis. The syndrome is thought to be a hypersensitivity complex that affects the skin and the mucous membranes. The majority of cases are idiopathic (without a known cause). The main known cause is certain medications, followed by infections and, rarely, cancers. The medical literature agrees that StevensJohnson syndrome (SJS) can be considered a milder form of toxic epidermal necrolysis (TEN). These conditions were first recognised in 1922. Both diseases can be mistaken for erythema multiforme. Erythema multiforme is sometimes caused by a reaction to a medication, but is more often a type III hypersensitivity reaction to an infection (caused most often by Herpes simplex) and is relatively benign.
Contributions by Arcadian, GorillaEye, and Keepcalmandcarryon.