Cyclosporine A has been shown to be a very versatile drug able to act on different diseases of immune pathogenesis. We present four cases of different drug-resistant dermatoses that showed no response to any of the previous treatments and that, because of the seriousness and extent of their clinical pictures, prompted us to use cyclosporine A. The dermatoses were the following: ulcerative lichen ruber planus, necrobiosis lipoidica, pyoderma gangrenosum and persistent light reaction. In all of the four cases the average attack dose was 4.5 mg/kg/day, which was gradually reduced. The treatment was then protracted for several months. The result was reepithelization of the ulcers and maintenance of the result after treatment suspension in necrobiosis lipoidica and in pyoderma gangrenosum. In the patients with erosive lichen ruber planus and persistent light reaction, cyclosporine A therapy provided a dramatic, although only temporary, improvement of the lesions. In all four patients, cyclosporine A proved to be an efficacious and manageable drug.
