Dermatomyositis is a relatively rare, nonsuppurative polymyositis of unknown cause with polymorphous cutaneous lesions of a nonspecific type which has been adequately described in the literature.*We propose, therefore, to present only the unusual features and unusual associated conditions, and to relate our experiences with steroids in the treatment of this disease. From the records of 394 patients who were seen at the Mayo Clinic from 1916 through 1954 with diagnoses of dermatomyositis, polymyositis, poikilodermatomyositis, sclerodermatomyositis, poikilosclerodermatomyositis, generalized myositis, and generalized fibromyositis, we selected 270 as representative of classic dermatomyositis and as the basis of this report. An average of six patients per year was seen from 1916 to 1950, after which the average increased to 17 per year. A high of 25 patients was seen in 1953. Age and Sex Distribution There were 179 females and 91 males, giving a ratio of two females