Antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis encompasses 3 conditions: eosinophilic granulomatosis with polyangiitis (EGPA; formerly named Churg-Strauss syndrome), granulomatosis with polyangiitis (GPA; formerly named Wegener granulomatosis), and microscopic polyangiitis.1 Diagnosing ANCA-associated small-vessel vasculitis is challenging for clinicians because of its infrequ...
