Abstract Acute interstitial pneumonia (AIP) is a type of idiopathic interstitial lung disease that typically affects non-smokers without prior lung pathology, characterized by a brief prodrome with rapid progression of respiratory decline. While AIP is a diagnosis of exclusion, the presence of diffuse alveolar damage and clinical symptoms of acute respiratory distress syndrome (ARDS) are indicative of diagnosis. In the era of COVID-19, differentiating AIP from post-viral lung injury or secondary ARDS has become increasingly complex. We present a case of AIP following a recovery from SARS-CoV-2 infection, highlighting diagnostic challenges, histopathologic findings, and management. A 59-year-old female with a history of sick sinus syndrome status post permanent pacemaker, hypertension, hepatitis C, prior deep vein thrombosis, provoked pulmonary embolism, and recent COVID-19 infection presented for cardiothoracic evaluation and possible lung biopsy. Recently, she underwent pacemaker lead revision and developed post-procedural hypoxia, at which time she was diagnosed with COVID-19 pneumonia. She was treated on antibiotics and discharged on dexamethasone and supplemental oxygen. Over the next two months, she was evaluated for persistent dyspnea and hypoxia, later developing fevers up to 103 °F, refractory to acetaminophen. She denied cough, chest pain, night sweats, weight loss, or rash. When the fevers persisted, empiric doxycycline prescribed offered little improvement. Her hypoxia worsened despite increased oxygen supplementation. Chest imaging prompted further evaluation, and the patient underwent video-assisted thoracoscopic surgery with wedge resection of the right upper and middle lung. Pathology findings were consistent with AIP showing severe interstitial lung disease, diffuse alveolar damage, intra-alveolar fibrin and microvascular injury with intravascular thrombi and fibroblastic proliferation. Following surgery, her respiratory status gradually improved with high-flow nasal cannula. She was discharged on prolonged prednisone taper with close pulmonary follow-up. AIP is defined as a rapidly progressive form of idiopathic interstitial lung disease characterized by diffuse alveolar damage in the absence of an identifiable cause. It often presents with acute hypoxemic respiratory failure resembling ARDS. In this case, AIP developed following COVID-19, highlighting the potential for post-viral inflammatory lung injury to trigger diffuse alveolar damage. High-resolution CT imaging reveals bilateral ground-glass opacities and consolidation, but definitive diagnosis often requires surgical lung biopsy when clinical and radiographic findings are inconclusive. Management is primarily supportive with lung-protective ventilation strategies and corticosteroids, yet mortality remains 50% within six months of onset. Early recognition and a multidisciplinary approach is essential to optimize recovery and prognosis. This abstract is funded by: none
Salama et al. (Fri,) studied this question.