Fulminant anti-nuclear matrix protein 2 antibody-positive dermatomyositis with massive anasarca, bulbar involvement and respiratory failure: recovery after prolonged immunosuppression and rehabilitation.

Dermatomyositis (DM) is an idiopathic inflammatory myopathy with cutaneous and systemic manifestations influenced by autoantibody profiles. We report a rare case of anti-nuclear matrix protein 2 (anti-NXP2)-antibody-positive DM in a previously healthy man in his 30s presenting with fulminant proximal muscle weakness, severe dysphagia requiring percutaneous endoscopic gastrostomy, massive anasarca (>30 kg fluid overload), respiratory failure requiring mechanical ventilation and tracheostomy, and characteristic cutaneous manifestations. MRI demonstrated diffuse myositis and elevated muscle enzymes with anti-NXP2 antibody positivity supporting the diagnosis. Treatment with pulse corticosteroids, intravenous immunoglobulin and subsequent azathioprine resulted in biochemical and clinical improvement, although the course was complicated by pulmonary embolism, pneumonia and gastrointestinal bleeding. Following prolonged immunosuppression and intensive multidisciplinary rehabilitation, the patient achieved substantial functional recovery. This case highlights the potential reversibility of even fulminant anti-NXP2-positive DM with timely aggressive treatment and rehabilitation.