Abstract
Systemic lupus erythematosus (SLE) is an autoimmune systemic disease that presents a diagnostic challenge due to a wide range of clinical manifestations affecting multiple organs. Particularly rare is its presentation with diffuse alveolar hemorrhage (DAH), a severe complication that arises from the disruption of the capillary-alveolar barrier and can rapidly progress to a life-threatening condition. We report a case of a 57-year-old female who presented to the emergency department experiencing dyspnea and hemoptysis. Her initial evaluations revealed anemia and thrombocytopenia, with high-resolution computed tomography scans showing diffuse bilateral infiltrates indicative of DAH. The findings led to the diagnosis of previously unrecognized SLE. This case underscores the importance of considering SLE in the differential diagnosis of DAH, emphasizing the necessity for prompt diagnostic workup and aggressive treatment in such critical presentations to improve patient outcomes.