A case of Mi2+ve refractory dermatomyositis

Background: Dermatomyositis (DM) is a rare autoimmune inflammatory myopathy characterized by proximal muscle weakness and distinctive cutaneous features. Atypical presentations such as rapidly progressive lower motor neuron (LMN) quadriparesis with respiratory failure are exceedingly rare and diagnostically challenging.Case Presentation: We report a case of a middle-aged male who presented with subacute onset (Over 2 months) of proximal and distal muscle weakness, dysphagia, and cutaneous rashes and weight loss. Clinical evaluation and electromyography confirmed myopathic changes. Laboratory findings revealed elevated creatine kinase levels (18000) and positive myositis-specific antibodies including anti-Mi-2 and anti-Ku. Despite initial immunotherapy with intravenous immunoglobulin (IVIG) and corticosteroids, the patient continued to worsen with quadriplegia and dysphagia and had to be electively intubated and ventilated. Subsequently, rituximab was administered, 2 doses of 1 gm at 2 weeks interval leading to gradual stabilization. The patient’s course was complicated by ventilator-associated pneumonia and autoimmune hemolytic anemia. Echocardiography showed poor left ventricular function, possibly reflecting myocarditis-related involvement. The patient was ultimately discharged in stable condition with planned long-term immunosuppressive therapy, 3rd dose of rituximab at 6 months.Conclusion: This case highlights an unusually aggressive form of anti Mi2+ve dermatomyositis showing poor response to steroids and IV Immunoglobulin.