New therapeutic approaches in atopic dermatitis.

Novel approaches to the therapy for atopic dermatitis (AD) can now be considered because of recent advances in the pathogenesis of the disease. Several of these concepts are being tested in clinical trials. The effectiveness of cyclosporin A, plus reports of adoptive transfer of AD, or its clearing, following bone marrow transplantation, verify the criticalness of immune cells in AD pathogenesis. Thus, there is renewed interest in immunosuppressives, such as azathioprine and methotrexate, as well as new adhesion molecule and T-cell activation inhibitors. Therapy with the T-cell lymphokine, interferon-gamma, or the thymic hormone, thymopentin, is designed to inhibit the IL-4-dominated response of AD T-cells. This approach, rather than directly suppressing all immune responsiveness, represents a more specific targeting to improve the balance of a chronically disordered immune response. Recent findings of a therapeutic advantage of longer-wavelength phototherapy over UVB therapy may relate to specific immunologic events following UVB vs UVA photoinjury that are critical to the exacerbation of AD. Complex herbal mixtures used in traditional Chinese medicine are currently being evaluated, but toxicity and palatability may be limiting. Other dietary approaches, such as modifying the lipid balance, have generally not had much benefit. Because the safety and efficacy of the above treatments need further exploration, the physician must continue to utilize fundamental methods, such as mitigating trigger factors (i.e., microbes and stress, and certain foods in persons with documented sensitivity), on improving the abnormal epidermal lipid barrier to irritation, and on reducing cutaneous inflammation with mild topical steroids.