Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Pemphigus vulgaris ?
    ### Response:
    What causes pemphigus vulgaris? Pemphigus vulgaris is an autoimmune disorder. The immune system produces antibodies against specific proteins in the skin and mucous membranes. These antibodies create a reaction that cause skin cells to separate. Although it is rare, some cases of pemphigus vulgaris are caused by certain medications.
    