S4368 Immune-Mediated Necrotizing Myopathy in a Young Woman With Dysphagia Necessitating PEG Tube Placement

Introduction: Immune-mediated necrotizing myopathy (IMNM) is a rare form of myopathy. While many patients with myositis profess to some form of dysphagia, there is limited information regarding the timeline of this progression and the ultimate need for a percutaneous endoscopic gastrostomy (PEG) tube for nutritional support. We present a case of a young woman with newly diagnosed necrotizing myositis and dysphagia necessitating transient PEG tube placement. Case Description/Methods: A 33-year-old woman with a history of central venous sinus thrombosis and necrotizing myositis diagnosed after acute muscle weakness and elevated CK levels >14,000 IU/L presented with 11 months of worsening dysphagia. Initially, she was treated for post-viral rhabdomyolysis with subsequent muscle biopsy confirming necrotizing myositis and genetic testing revealing positive anti-SRP autoantibodies. Although she had moderate improvement with IVIG and high-dose prednisone, her dysphagia and odynophagia persisted, resulting in a 45-pound unintentional weight loss. Initial solid food dysphagia progressed to difficulty tolerating soft foods. A Gastroenterology consultation was obtained to address nutritional support. The patient elected to proceed with PEG tube placement. The esophagogastroduodenoscopy revealed normal esophagus, stomach, and duodenum. She was closely monitored and within 6 months she was able to tolerate oral intake and the PEG tube was successfully removed. Discussion: The etiology of IMNM is unclear, although it is believed to be related to genetic and environmental factors. The typical onset of IMNM symptoms is between the ages of 40-60 years. Dysphagia is a relatively common symptom in inflammatory myopathies, it only occurs in 20%-30% of individuals with IMNM. When IMNM-associated dysphagia occurs, it usually presents later in disease progression. This case illustrates the severity and variability of IMNM-associated dysphagia. The early onset, rapid progression, and refractory dysphagia in a young patient with newly diagnosed IMNM is rare and highlights the importance of recognizing atypical presentations to ensure early intervention which can prevent complications and improve patient outcome.