Topical cyclosporin A treatment in psoriasis and other dermatological diseases: Theoretical and practical aspects.

The immunosuppressive properties of cyclosporin A (CyA) in systemic (oral) administration are now well documented in several dermatological disorders, especially in psoriasis. However, long-term oral use, even at low doses, is hampered by renal side-effects. From a theoretical point of view, in skin diseases there is the opportunity to bypass the oral route and administer CyA directly to the affected areas. In this review results from experimental studies to date in psoriasis, alopecia, contact and atopic dermatitis, oral lichen planus and keloid scars are summarized. Theoretical considerations on the pharmacokinetics of CyA for topical application are also discussed.