Systemic and local administration of cyclosporine in the treatment of psoriasis. Since 1984, cyclosporine has been used increasingly for indications other than in prophylaxis of transplant rejection. Current awareness that psoriasis is, at least in part, a T cell-mediated condition has led to the initiation of several studies of cyclosporine's role in the treatment of this disease. The remarkable efficacy of systemically administered cyclosporine, even in severely refractory cases of psoriasis, has not only provided us with a new therapeutic option but also has helped further our understanding of the pathophysiology of psoriasis. Although it has been hailed as a breakthrough, systemic cyclosporine usage is associated with undesirable sequelae, principally hypertension and decreased renal function. These effects limit its more widespread use. This review assesses current knowledge of the capabilities and prospects of systemic cyclosporine in the treatment of psoriasis, as well as the status of topical preparations. 