Use of the newer immunosuppressive agents in dermatology.

Immune mechanisms play a central role in various diseases such as eczema and psoriasis, and in the past treatment tended to involve corticosteroids and cytostatic drugs. Organ transplantation has stimulated the development of newer immunosuppressants, some of which have also been found to be efficacious in the inflammatory dermatoses. The best studied such immunosuppressant is cyclosporin, which has shown efficacy especially in psoriasis and atopic dermatitis. The major limiting factor in the use of cyclosporin is its adverse effects, especially nephrotoxicity and hypertension. Therefore the risk : benefit ratio should always be considered before initiation of cyclosporin therapy, and the patient should be carefully followed for such adverse effects. Tacrolimus seems to share the efficacy and most of the adverse effects of cyclosporin when used systemically, presumably because of its similar intracellular mechanism of action. Unlike cyclosporin, tacrolimus is efficacious topically, which may allow lower systemic adverse effects to be combined with higher local efficacy. Other newer immunosuppressants include sirolimus (rapamycin) and monoclonal antibodies. Their use in dermatology is still in the research phase, and no conclusions about their clinical potential can yet be made.