Diffuse Alveolar Hemorrhage in Systemic Lupus Erythematosus: An Updated Clinical Perspective on a High-Mortality Complication

Diffuse alveolar hemorrhage (DAH) is a rare but devastating complication of systemic lupus erythematosus (SLE), often presenting with acute respiratory failure and carrying high mortality. Clinical recognition is challenging, as hemoptysis may be absent, and early features can overlap with infection or other causes of acute respiratory distress syndrome (ARDS). Diagnosis relies on a high index of suspicion, supported by imaging and bronchoalveolar lavage, while promptly excluding infectious etiologies. Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis remains the most important differential diagnosis. Management is largely based on observational data and requires early, aggressive immunosuppression with high-dose glucocorticoids and additional agents such as cyclophosphamide or rituximab. In refractory cases, adjunctive therapies and extracorporeal membrane oxygenation (ECMO) may be lifesaving. Despite therapeutic advances, outcomes remain poor, underscoring the need for early recognition and timely intervention.