Polymyositis is a systemic and idiopathic inflammatory myopathy that, besides muscle manifestation, may occur with respiratory involvement, gastrointestinal tract and rarely renal involvement. In this latter, there are only two cases of IgA nephropathy, but both in dermatomyositis. On the other hand, we reported, for the first time, a case of IgA nephropathy in polymyositis.
Inflammatory myopathy; IgA nephropathy; Polymyositis; Case report