Therapy of dermatologic disease with cyclosporin A

Cyclosporin A is a potent immunosuppressive drug with almost a decade of clinical use. Due to its lack of bone marrow toxicity, it has assumed a leading role in organ transplant surgery. Likewise, it has shown remarkable efficacy in psoriasis and has shown potential usefulness in other dermatologic diseases, most of which are thought to have an autoimmune T-cell-mediated pathogenesis. There are many other inflammatory skin conditions in which T lymphocytes represent a majority of the cellular infiltrates, and theoretically such disorders may be responsive to CsA. Diseases such as lichen planus, allergic contact dermatitis, photoallergy, and vitiligo are potential areas of further study. The potential use of topical and intralesional CsA also warrants further clinical evaluation. There are reports of topical CsA showing effectiveness for alopecia areata and nickel contact sensitivity. Griffiths et al. treated six psoriatic patients with 2% CsA ointment twice daily for 4 weeks. The response to placebo or CsA at the end of the study was similar in all patients. Notably, there was no measured systemic absorption and no change in blood pressure or renal function. We had similar unimpressive results in several patients treated with a 10% solution of CsA; minimal to no response was seen. Of great benefit would be an effective topical preparation without systemic absorption or toxicity. Future studies will need to carefully evaluate the vehicle used and the strength of topical CsA employed. The role of CsA in dermatologic disease still needs much investigation, both at the clinical and basic science levels. The studies to date show dramatic and exciting results. Indeed, CsA may well represent a major advance in the understanding and treatment of psoriasis. However, the decision to use CsA for nonfatal diseases such as psoriasis will require a careful balance between efficacy and toxicity. If long-term side effects can be avoided or kept within reasonably safe, acceptable limits, CsA holds great promise for the treatment of psoriasis. It may at times be used as an acute intervention, with a relatively large, initial dose for a short period of time to quickly clear severe psoriasis. This could be followed by either a reduction to a lower and safer maintenance dose or a program of other treatments. Cyclosporin A may also prove useful alone in very low doses or in combination therapy, as with UVB or PUVA. Optimal dosing protocols are currently under investigation.