Synopsis
Idiopathic inflammatory myopathies (IIM) involve inflammation of the muscles and are classified based on the patterns of presentation and immunohistopathologic features on skin and muscle biopsy into four categories: dermatomyositis, polymyositis, inclusion body myositis, and immune mediated necrotizing myopathy. The term “scleroderma” refers to fibrosis of the skin. Localized scleroderma (morphea) is skin-limited, while systemic sclerosis (SSc) is associated with vascular and internal organ involvement. Although there is a paucity of randomized clinical trials, treatment with systemic corticosteroids (CS) is the standard of care for IIM with muscle and organ involvement. The extra-cutaneous features of systemic sclerosis are frequently treated with CS, however high doses have been associated with scleroderma renal crisis in high-risk patients. CS monotherapy is neither recommended for the cutaneous manifestations of dermatomyositis nor scleroderma. While CS can be effective first line agents, their significant side effect profile encourages concomitant treatment with other immunosuppressive medications to enable timely tapering.