Therapeutic evolution and outcomes in EGPA complicated by diffuse alveolar haemorrhage: Case-based review.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare, systemic vasculitis characterised by asthma, eosinophilia, and multi-organ involvement. Diffuse alveolar haemorrhage (DAH) is an uncommon, but life-threatening pulmonary complication in EGPA. We report on a 49-year-old, previously healthy woman who presented initially with asthma-like symptoms and later developed a fever, haemoptysis, cutaneous purpura, and periorbital oedema. Laboratory evaluation revealed marked eosinophilia, anaemia, elevated inflammatory markers, and a strongly positive MPO-ANCA. Bronchoalveolar lavage fluid was haemorrhagic and contained hemosiderin-laden macrophages, indicating DAH. Broad-spectrum antibiotics were empirically initiated but discontinued after metagenomic next-generation sequencing (mNGS) of the bronchoalveolar lavage fluid excluded infection. A bone marrow biopsy showed eosinophilic hyperplasia without clonal mutations. A diagnosis of MPO-ANCA positive EGPA with DAH was established. The patient received pulse methylprednisolone, prednisone, intravenous immunoglobulin, mepolizumab, and rituximab. Clinical symptoms improved rapidly, and radiological signs of alveolar haemorrhage had nearly resolved within days. Our case illustrates that the integration of rituximab and mepolizumab with corticosteroids can achieve rapid remission and steroid sparing in EGPA-DAH. While evidence remains limited to case reports and small series, targeted biologics may fundamentally improve outcomes in this high-risk subset. Prospective studies are warranted to define optimal treatment strategies.