Treatment-resistant inflammatory myopathy

When confronted with a dermatomyositis or polymyositis patient not responding to immunosuppressive treatment, physicians must first ask whether the original diagnosis was correct. In this review, we provide a guide to the clinical features and ancillary tests, which might be helpful in the differential diagnosis of myositis. Particular attention is paid to the role of autoantibody detection, as some of them are not only relatively specific for the disease but also associated with unique clinical features including resistance to treatment. Subsequently, other possible explanations of treatment resistance are listed and a short overview of treatment options for resistant myositis patients is given.