Diffuse Alveolar Hemorrhage Linked to Hydralazine.

Hydralazine, a commonly prescribed vasodilator for hypertension, is associated with adverse effects such as vasculitis, glomerulonephritis, and drug-induced lupus. We present a rare case of hydralazine-induced diffuse alveolar hemorrhage (DAH) in a 74-year-old male with a history of hypertension. The patient was admitted with symptoms including hemoptysis, dyspnea, and dark urine. Initial findings included a biopsy-confirmed leukocytoclastic vasculitis, elevated MPO antibodies, and evidence of DAH on bronchoscopy. Despite the absence of glomerulonephritis, the patient exhibited signs of pulmonary-renal syndrome, including worsening renal function and anemia. The patient's condition improved significantly after cessation of hydralazine and initiation of intravenous methylprednisolone. This case underscores the importance of considering hydralazine-induced ANCA vasculitis in patients presenting with unexplained pulmonary hemorrhage, particularly when other common causes are ruled out. Early recognition and management are crucial to prevent potentially life-threatening complications associated with this rare condition.