Stevens Johnson syndrome is also known as Erythema multiforme. Stevens Johnson syndrome is the disorder of the skin due to allergic reaction. In this disorder cell death occurs to such extent which ultimately leads to the separation of epidermis from the dermis. This is the life threatening disorder. This is a type of hypersensitivity reaction which occurs due to drugs or infections. Drugs include sulfonamides, penicillins, barbiturates and phenytoin while infections include mycoplasma and herpes simplex.