Current Essentials in Inflammatory Myopathies

Inflammatory myopathies are a heterogeneous group of acquired systemic diseases, which include dermatomyositis (DM), polymyositis (PM), necrotising myopathy (NM) and inclusion body myositis (IBM). All four disease entities share certain clinical characteristics, such as progressive muscle weakness and elevated muscle enzymes. Other characteristic-associated features such as skin involvement in DM or the detection of myositis-specific antibodies, may be indicative of a particular subtype. However, muscle biopsy is still essential for the diagnosis and shows distinct histopathological characteristics for each subtype of myositis. Treatment of inflammatory myopathies is still based on clinical experience, since placebo-controlled trials are scarce. While DM, PM and NM respond well to immunosuppressive treatment, IBM is usually resistant to immunotherapy. This review aims to give a concise overview and provide guidance for general management of myositis.