<prompt> Steven-Johnson syndrome involvesType I hypersensitivity reactionType II hypersensitivity reactionType III hypersensitivity reactionType IV hypersensitivity reaction  <response>: Both erythema multiformae and steven Johnson syndrome are due to deposition of immune complexes in the superficial microvasculature of skin and mucosa. These immune complex diseases are mediated through type III hypersensitivity reaction. 