Below is an instruction from Human. Write a response.
    ### Instruction:
    How many people are affected by Stevens-Johnson syndrome/toxic epidermal necrolysis ?
    ### Response:
    SJS/TEN is a rare disease, affecting 1 to 2 per million people each year. Stevens-Johnson syndrome (the less severe form of the condition) is more common than toxic epidermal necrolysis.  People who are HIV-positive and those with a chronic inflammatory disease called systemic lupus erythematosus are more likely to develop SJS/TEN than the general population.
    