Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Psoriasis ?
    ### Response:
    Psoriasis (sow RYE uh sis) is a chronic skin disease. Chronic means that it lasts a long time, often a lifetime. Psoriasis affects more than 5 million adults in the United States. It appears about equally in males and females. Psoriasis occurs when the skin cells grow too quickly.
    