Immunosuppressive agents in dermatology. An update.

Azathioprine, cyclophosphamide, methotrexate, and cyclosporine are the immunosuppressive agents most commonly used by dermatologists. Azathioprine has a relatively good safety profile and is therefore often preferred for the treatment of chronic eczematous dermatitides and bullous disorders. Awareness of the role of genetic polymorphisms in its metabolism can increase the efficacy and safety of this drug. Cyclophosphamide is an antimetabolite that has a more rapid onset of immunosuppressive effect than azathioprine, but has significant short-term and long-term toxicity. It is of use in fulminant, life-threatening cutaneous disease. Methotrexate is an antimetabolite that has significant anti-inflammatory activity. Despite its hepatotoxicity, its role in inflammatory dermatoses is broadening. Likewise, the role of cyclosporine is being expanded. This drug has potent T-cell inhibitory effects secondary to interference with intracellular signal transduction. Given the evidence for cumulative renal toxicity, it currently has a role in the short-term treatment of refractory psoriasis and atopic dermatitis, as well as in select inflammatory dermatoses. Familiarity with disease-specific clinical efficacy, side-effect profile, and dosage allows the successful and judicious use of these drugs in dermatologic disorders.