Introduction: Rheumatic pathologies represent a small percentage of deaths related to respiratory issues. Dermatomyositis is an idiopathic inflammatory myopathy that is part of a heterogeneous group of muscular diseases of unknown etiology. It is characterized by progressive muscle weakness and inflammation, often accompanied by skin alterations, elevated creatine kinase levels, presence of serum autoantibodies, and inflammatory infiltrates in muscle biopsy. Dermatomyositis has been associated with more than 20 distinct antibodies. Although some variants progress rapidly and are associated with interstitial pulmonary involvement, such as those associated with myositis-specific autoantibodies, anti-signal recognition particle, and anti-topoisomerase I. In the literature, anti-Mi-2β dermatomyositis does not seem to be related to pulmonary involvement, and its five-year mortality is less than 5%, showing an excellent response to treatment and a favorable outcome. Case Description: This concerns a 54-year-old woman with a history of hypothyroidism and anti-Mi-2β dermatomyositis who discontinued treatment. She was admitted due to rapidly progressive and unusually fulminant respiratory failure, diagnosed with an exacerbation of the autoimmune pathology. Treatment was initiated with cyclophosphamide and methylprednisolone. During her stay in the Intensive Care Unit, she experienced worsening oxygenation, requiring invasive mechanical ventilation and the initiation of broad-spectrum antibiotics. Conclusions: Acute respiratory failure can be a significant complication in rheumatic diseases. Although the majority of patients with autoimmune diseases do not develop clinically evident pulmonary involvement, these systemic disorders contribute to a small percentage of deaths from all respiratory causes. Dermatopolymyositis represents a rare cause of respiratory failure that may pose a diagnostic dilemma for the physician. Additionally, variants associated with low mortality are often overlooked due to their low progression to respiratory failure, leading to the underestimation of their potential lethality and, at times, fatal outcomes. The patient's case exemplifies that even less severe myopathies can compromise the lungs, leading to rapidly progressive respiratory failure.