CUTANEOUS CHANGES OF DERMATOMYOSITIS IN PATIENTS WITH NORMAL MUSCLE ENZYMES - DERMATOMYOSITIS SINE MYOSITIS

Background: Dermatomyositis sine myositis may have various connotation s. Controversy exists as to nomenclature, degree of evaluation require d, therapy, and course (e.g., does true dermatomyositis of the skin on ly exist?). Objective. The purpose of this study was to assess prospec tively patients with the clinicopathologic features of dermatomyositis and normal muscle enzyme serum levels to determine their course in te rms of the onset of muscle disease. Methods: Thirteen patients were st udied by complete history and clinical examination, laboratory studies , electromyography, and skin and muscle biopsy. They were observed for 1 to 6 years. Results. Patients were classifiable into three groups: (1) cutaneous changes only, (2) cutaneous changes only at baseline wit h subsequent development of myositis, and (3) cutaneous changes with n ormal muscle enzyme serum levels at baseline but with myositis demonst rated by electromyography and/or muscle biopsy specimens. Conclusion: Significantly different prognostic and therapeutic implications are pr esent in patients with dermatomyositis with normal muscle enzyme serum levels depending on the results of electromyography, muscle biopsy, a nd clinical observation.