Dermatomyositis: Clinical features and pathogenesis.

Dermatomyositis (DM) is an idiopathic inflammatory myopathy that is clinically heterogeneous and that can be difficult to diagnose. Cutaneous manifestations sometimes vary and may or may not parallel myositis and systemic involvement in time course or severity. Recent developments in our understanding of myositis-specific antibodies have the potential to change the diagnostic landscape of DM for dermatologists. Although phenotypic overlap exists, anti-Mi2, -MDA5, -NXP2, -TIF1, and -SAE antibodies may be correlated with distinct DM subtypes in terms of cutaneous manifestations, systemic involvement, and malignancy risk. This review highlights new findings on the DM-specific myositis-specific antibodies and their clinical associations in both adults and children.