Recurrent stroke in eosinophilic granulomatosis with polyangiitis: the need to consider additional mechanisms beyond vasculitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare antineutrophil cytoplasmic antibody-associated vasculitis that typically presents with asthma, eosinophilia and small-to-medium vessel inflammation. Central nervous system infarction is an uncommon complication and typically occurs during active disease. Recurrent stroke despite apparent disease remission is rare and presents a diagnostic challenge.

We report a man in his 60s with EGPA who developed recurrent multifocal cerebral infarcts. His initial presentation occurred in the context of marked eosinophilia and systemic inflammation, consistent with active vasculitis. However, subsequent cerebrovascular events occurred despite well-suppressed eosinophil counts and inflammatory markers. His later course was complicated by pulmonary embolism, iliac vein thrombosis, nephrotic-range proteinuria and autoimmune serological abnormalities, raising suspicion of a superimposed prothrombotic state. Renal biopsy, performed in view of nephrotic syndrome and initial autoimmune serology, demonstrated neural epidermal growth factor-like 1 protein membranous glomerulonephritis—to our knowledge a previously unreported association with EGPA.

This case highlights the complexity of stroke mechanisms in EGPA and emphasises the importance of reconsidering alternative or additional contributors when cerebrovascular events recur despite apparent disease control.