Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Stevens-Johnson syndrome/toxic epidermal necrolysis ?
    ### Response:
    Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a severe skin reaction most often triggered by particular medications. Although Stevens-Johnson syndrome and toxic epidermal necrolysis were once thought to be separate conditions, they are now considered part of a continuum.
    