Recalcitrant steroid-resistant EGPA with multisystem involvement

Eosinophilic granulomatosis with polyangiitis (EGPA) is a multisystem disorder classically characterized by sequential histopathologic and clinical disease phases. An eosinophilic tissue infiltration phase typically precedes the development of a systemic small-vessel vasculitic phase. The contribution of these two pathogenic mechanisms to disease course and the boundaries between them are often blurred. We report the case of a 49-year-old man with established p-ANCA positive EGPA presenting acutely with central and peripheral nervous system dysfunction, diffuse alveolar hemorrhage, biopsy-proven myositis, and myocarditis resistant to steroids. The patient’s clinical course was marked by unremitting abdominal pain associated with significant weight loss. Although eosinophilic infiltrates were not observed on gastrointestinal mucosal biopsy, samples stained heavily for eosinophil peroxidase, indicating prior degranulation of eosinophils. Complete remission of eosinophil-mediated tissue infiltration and vasculitic phases was achieved only after the addition of intravenous cyclophosphamide to corticosteroid therapy. This case report demonstrates both: a) the importance of recognizing eosinophilic degranulation in addition to intact eosinophils in tissue and b) a unique presentation of a rare disease, underscoring the multifaceted and heterogeneous nature of EGPA and its overlapping disease phases.