<unk>  is a life-threatening condition affecting the skin, in which due to cell death the epidermis separates from the dermis.  The syndrome is thought to be a hypersensitivity complex affecting the skin and the mucous membranes.  Although the majority of cases are idiopathic, the main class of known causes is medications, followed by infections and (rarely) cancers.
Stevens-Johnson syndrome
Staphylococcal scalded skin syndrome
Sweet's syndrome
Toxic epidermal necrolysis
Drug eruption
Subacute cutaneous lupus erythematosus
Factitious dermatitis
Papular purpuric gloves and socks syndrome