ABSTRACT
Since the cause of psoriasis is still unknown, no single therapy directed at a specific causative factor has been developed. Indeed, it is unlikely that there is a single biochemical abnormality in psoriasis that could be corrected. Nevertheless, cyclosporine has had a major impact on psoriasis therapy and research. Besides being extremely effective itself (1-24) in the treatment of psoriasis, cyclosporine has inspired the search for other compounds that act in the same way. In addition, the efficacy of cyclosporine in the treatment of psoriasis (Fig. 1) has caused a substantial proportion of psoriasis research to shift from investigations into keratinocyte abnormalities to studies of the immune system (25).
