Clinically amyopathic dermatomyositis (CADM) is a rare entity of dermatomyositis. As a rule, CADM presents without muscular involvement. Thus, the level of creatine kinase is most commonly within the normal range. Dermal manifestations of CADM are Gottron’s papules and mechanic’s hands. In the case of melanoma differentiation-associated gene 5 intracellular pathogen sensor (MDa5 antibodies), CADM is often associated with a rapidly progressive and severe form of interstitial lung disease. Pulmonary function tests reveal restriction and hypoxemia of varying degree. Features of ground-glass opacities, reticulations and consolidations are detected in high-resolution CT scan. Lymphocytes are sometimes predominant in bronchioloalveolar lavage. Pathologists see a picture similar to non-specific interstitial lung disease or organizing pneumonia. Pronounced immunosuppression is the most common therapy. However, sometimes a combination of different immunosuppressive therapies is necessary. A novel strategy to treat CADM with rapidly progressive interstitial lung disease is the Janus kinase inhibitor tofacitinib. Treatment can be monitored with the level of ferritin and MDa5-antibody titer. Mortality is as high as 84 %.
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