TOPIC: Diffuse Lung Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Amyopathic Dermatomyositis (CADM) is a subtype of dermatomyositis (DM). These patients usually have only cutaneous findings of DM. One third may develop some degree of subclinical myositis. Findings include heliotrope rash, Gottron's papules, nail fold changes, and mechanic's hands. Numerous antibodies are known in the inflammatory myopathies but characteristic to CADM is anti-melanoma differentiation-associated protein-5 (MDA5). Patients with CADM can develop a rapidly progressive interstitial lung disease (ILD) when positive for anti-MDA5 or anti-synthetase antibodies. CASE PRESENTATION: 61-year-old female with diabetes mellitus, and occupational asthma who was working as a hospital housekeeper with exposure to bleach had been receiving multiple cycles of asthma regimens with unremarkable imaging of her chest since August 2019. In February 2020 she presented with dyspnea and cough. Computed tomography (CT) chest showed bibasilar infiltrates and minimal peripheral reticular markings. She was treated for pneumonia with transient improvement. Early April, she developed Gottron's papules, periungual changes, and worsening infiltrates and ground glass opacities raising suspicion for a rheumatological process. Workup was remarkable for ANA titer of 1:320 and myositis panel was positive for anti-MDA5 antibody. Bronchoalveolar lavage was negative for an infectious process and transbronchial lung biopsies were non-diagnostic. She was diagnosed with CADM with ILD and started on high-dose steroids and cyclophosphamide with transient improvement. She was discharged on steroids with subsequent plan to start steroid-sparing agents. However, early May she was readmitted to the hospital requiring mechanical ventilation. Despite receiving plasma exchange, her respiratory status declined and was unable to be extubated due to worsening hypoxia and lung mechanics. After being intubated for two weeks the family withdrew care and the patient died the same day. DISCUSSION: This patient presented with respiratory symptoms and CT chest findings compatible with ILD three months prior to her death and preceded the DM cutaneous lesions. Patient's with CADM, especially those with positive anti-synthetase or anti-MDA5 antibodies, are at risk for developing rapidly progressive ILD that can be fatal. Principles of treatment are yet not clearly defined but include aggressive immunosuppression with high-dose steroids in conjunction with cyclophosphamide, cyclosporine, or rituximab, and at times, tacrolimus or azathioprine are considered. CONCLUSIONS: This case demonstrates the importance of keeping ILD in the differential diagnosis of poorly explained chronic respiratory symptoms and that DM is one of several causes of this disease. REFERENCE #1: Dinulos, J. G. (2021). Habif's clinical DERMATOLOGY: A color guide to diagnosis and therapy. In Habif's clinical dermatology: A color guide to diagnosis and therapy (7th ed., pp. 669-712). REFERENCE #2: 2. Kanneboyina, N., Aggarwal, R., & Lundberg, I. E. (2021). Inflammatory Diseases of Muscle and Other Myopathies. In Firestein and Kelly's Textbook of Rheumatology (11th ed., pp. 1539-1568). Elsevier. doi:https://www.clinicalkey.com/#!/content/book/3-s2.0-B9780323639200000904?scrollTo=%23hl0001754 DISCLOSURES: No relevant relationships by Joel Barnett, source=Web Response No relevant relationships by Fernando Caceres, source=Web Response No relevant relationships by Sarah Mete, source=Web Response