Recurrent alveolar hemorrhage: How do you treat that which you cannot see?

Diffuse alveolar hemorrhage (DAH) is a rare and life-threatening event which is characterized by bleeding into the alveolar spaces of the lung. Etiology of DAH can be broadly divided into immune and non-immune mediated disease. In the absence of infection or malignancy, an immunological workup is required to find the cause of alveolar bleed. Rarely, there is a failure to establish a definitive etiology in patients with DAH. In those scenarios, patients who do not respond to steroids, plasmapheresis should be considered as a rescue treatment to prevent catastrophic outcomes. Herein, we present a unique case of a 48-year-old male admitted with DAH of unknown etiology completely recovered after empirical plasmapheresis.