B43-19 Rapidly Progressive Interstitial Lung Disease Secondary to Amyopathic Dermatomyositis

Abstract Introduction Rapidly Progressive Amyopathic Dermatomyositis (RP-ADM) is a rare subtype of dermatomyositis and is strongly associated with Rapidly Progressive Interstitial Lung Disease (RP-ILD). The presence of anti-melanoma differentiation-associated gene 5 antibodies in RP-ADM is highly correlated with RP-ILD, a combination known for its poor prognosis and high mortality. Complications include respiratory failure, pneumothorax, and pneumomediastinum. Treatment regimens often involve high-dose corticosteroids, immunosuppressants, IVIG, biologic therapies, and, in severe cases, plasma exchange. Description A previously healthy 38 year-old male presented with worsening shortness of breath, facial swelling and dry cough. He was diagnosed with MDA5-positive dermatomyositis with RP-ILD and pneumomediastinum. His hospital course was complicated by respiratory failure despite corticosteroid treatment requiring intubation, multiple pneumothoraces necessitating chest tube placement, and initiation of veno-venous ECMO for refractory hypoxemia. He was treated with aggressive immunosuppression (high-dose corticosteroids, IVIG, cyclophosphamide, tacrolimus, tofacitinib, and plasmapheresis). His course was further complicated by klebsiella and candida bacteremia. ECMO support stabilized his respiratory status, enabling tracheostomy and transition to high-flow oxygen. Encephalopathy, delirium, and agitation during sedation weaning remain a barrier to lung transplantation evaluation. Discussion Classic dermatomyositis typically presents with symmetrical proximal muscle weakness, Gottron’s papules, heliotrope rash, and other cutaneous features. Systemic involvement may affect major organ systems. In contrast, RP-ADM is characterized by cutaneous findings without muscle weakness or elevated muscle enzymes, making diagnosis more challenging. This case illustrates not only a rare manifestation of an already uncommon disease but also the extensive complications and therapeutic challenges it accompanies. In this patient, vv-ECMO was lifesaving in the context of refractory respiratory failure, serving as a bridge to lung transplantation, which remains the only definitive treatment option at this advanced stage. One dilemma is if the infectious risk of immunosuppression outweighs the benefits in a patient requiring vv-ECMO whose lungs are not salvageable from advanced disease. Challenges persist in optimizing the patient’s condition for transplant candidacy. Efforts to reduce sedation and assess neurologic status result in agitation, leading to disruptions in ECMO flow and critical oxygen desaturations. Balancing hemodynamic stability with the risks of sedation and deconditioning remains a persistent dilemma and major barrier to transplantation evaluation. This abstract is funded by: none