Hyperpigmentation Due to Cyclosporine Therapy.

For a myriad of immune disorders, cyclosporine has demonstrated marked efficacy in relieving clinical symptoms and reversing pathological developments. We present a case of hyperpigmentation induced by cyclosporine therapy used to treat prurigo nodularis, an extremely rare adverse effect of cyclosporine that has been reported only once, to our knowledge, in the dermatologic literature. After four months of cyclosporine therapy, our patient developed noticeable hyperpigmentation on the dorsal hands and feet and to a lesser degree on her arms and legs. Prior research has discovered a dose-dependent decrease in tyrosinase activity and pigment formation in cultured melanocytes due to cyclosporine - an effect opposite to what was observed in our case. Thus, further study into this relationship is necessary. In essence, physicians should be aware of unwanted cutaneous changes after the initiation of cyclosporine therapy and may want to counsel patients about the importance of ultraviolet (UV) radiation protection.