Eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss syndrome): where are we now?

Antineutrophil-cytoplasm antibody (ANCA)-associated vasculitides (AAV), classified as small-sized vessel vasculitides, include: granulomatosis with polyangiitis (GPA) (formerly Wegener’s granulomatosis disease), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA) (formerly Churg–Strauss syndrome) [1]. Although they share some common features, EGPA has certain specificities, namely asthma, blood and tissue eosinophilia, and frequent ear, nose and throat (ENT) involvement, while ANCA (targeting neutrophil myeloperoxidase) are found in only a subset of patients (30–70%) [2, 3]. Moreover, EGPA diagnosis can be challenging, as its manifestations can overlap with those of primary hypereosinophilic syndromes (HES) [4].