SESSION TITLE: Wednesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Granulomatosis with polyangiitis (GPA) is an antineutrophilic cytoplasmic antibody-associated small-vessel vasculitis affecting, but not often limited to, the upper respiratory tract, lungs, and kidneys. Pulmonary involvement varies in clinical presentations and chest imaging findings, making differentiation from pulmonary infections difficult. Granulomatosis with polyangiitis can clinically resemble Adult Respiratory Distress Syndrome (ARDS). This case highlights the challenges encountered in managing an atypical presentation of GPA mimicking ARDS CASE PRESENTATION: We present a case of 45-year-old female with history of chronic sinusitis, recurrent pneumonia and recent diagnosis of granulomatosis with polyangiitis. She presented with progressive shortness of breath, fever, and hypoxia. Initial labs revealed leukocytosis, elevated inflammatory markers and high c-ANCA titers. Her respiratory function worsened after admission and was subsequently intubated. She was diagnosed with severe ARDS due to the presence of bilateral infiltrates, P/F ratio < 100 mmHg, and high PEEP. Her imaging demonstrated pneumatocoeles on the left lower lobe (Figure 1). She received IV broad-spectrum antibiotics, however her respiratory function showed little improvement. She underwent bronchoscopy after intubation and no gross hemorrhage was seen. The bronchial alveolar wash showed elevated WBC levels, no RBCs, no organisms, and cultures were negative. On day 3 post-intubation, she was started on IV cyclophosphamide and high-dose steroids for 6 days, with remarkable improvement of respiratory status noted thereafter. Repeated labs revealed normalization of inflammatory markers and c-ANCA titers. The patient was successfully extubated after 10 days of mechanical ventilation support. DISCUSSION: ARDS comprises an unusual manifestation of this disease flare which can easily go undiagnosed. This case is notable not only for its rarity and benign course after successful treatment with immunosuppressive medications but also for the challenging differential diagnosis. Given the patient’s history of recurrent infections, acute presentation with elevated WBC, inflammatory markers, and fever, distinguishing infectious causes of ARDS from the acute flare of the underlying GPA was a challenge. CONCLUSIONS: Symptom persistence after antibiotic therapy is strongly suggestive of GPA flare even in the absence of pulmonary hemorrhage. Heightened suspicion when treating severe pulmonary failure in patients with GPA can contribute to an earlier diagnosis, better management, and potentially prevent life-threatening pulmonary injury. Reference #1: Tarabishy AB, Schulte M, Papaliodis GN, Hoffman GS. Wegener's granulomatosis: clinical manifestations, differential diagnosis, and management of ocular and systemic disease. Surv Ophthalmol. 2010;55(5):429-44. https://doi.org/10.1016/j.survophthal.2009.12.003. Reference #2: Nasser M, Cottin V. The respiratory system in autoimmune vascular diseases. Respiration. 2018;96(1):12-28. https://doi.org/10.1159/000486899. Reference #3: Reback M, Rahman RA, Donatelli C, Schilz RJ. A Case of Granulomatosis with Polyangiitis Masquerading as Fungal Pneumonia. Am J Resp Crit Care Med. 2018;197:A3057. DISCLOSURES: No relevant relationships by Saif El Naser El Nawaa, source=Web Response No relevant relationships by Mohamed Elmassry, source=Web Response No relevant relationships by Adnanul Karim, source=Web Response No relevant relationships by John Makram, source=Web Response No relevant relationships by Haneen Mallah, source=Web Response No relevant relationships by Victor Test, source=Web Response