Clinically amyopathic dermatomyositis (CADM) is a subset of dermatomyositis (DM) that has conventional cutaneous manifestations of DM, but paradoxically, little or no muscle involvement. In 2005, a novel antibody was described in association with CADM - anti-melanoma differentiation-associated gene 5 (anti-MDA5). Patients with this serologic marker have a characteristic mucocutaneous phenotype ...