Steroid Induced Myopathy in Dermatomyositis Patients

ABSTRACT

Symmetrical proximal weakness and characteristic dermatologic manifestations are important in the diagnosis of dermatomyositis. We report a case of atypical presentation of dermatomyositis due to previous steroid use and also report steroid-induced myopathy which may occur from steroid administration during the course of treatment. A 77-year-old man, previous steroid user, showed rapidly progressing weakness after abruptly stopped medication. He has presented erythematous papule on face and anterior chest but no heliotrope rash and Gottron's papules were observed. Muscle enzyme (creatine kinase) concentration is increased, and needle electromyography shows increased spontaneous activity on proximal limb muscle. The muscle biopsy confirmed dermatomyositis. During the course of treatment, he revealed persistent weakness despite the continuous steroid use and stable creatine kinase level. Electrodiagnostic study suggests steroid-induced myopathy and after tapering steroid, proximal muscle strength improved. This case reports the effect of steroid use on dermatomyositis patients and a process of diagnosing coexisting steroid induced myopathy during treatment.