Granulomatous Vasculitis.

Vasculitides are uncommon disorders, characterized by inflammation of the blood vessels resulting either in ischemia or hemorrhage. They are commonly classified as small-, medium-, or large-vessel vasculitides. Antineutrophil cytoplasmic antibody-associated vasculitis is an important group of small-vessel vasculitis. This group includes granulomatous vasculitides, namely, granulomatosis with polyangiitis (GPA), eosinophilic granulomatosis with polyangiitis (EGPA), and nongranulomatous vasculitis, namely, microscopic polyangiitis (MPA). Classic polyarteritis nodosa (PAN) is a granulomatous medium-vessel vasculitis. This review discusses the classification, etiopathogenesis, clinical features, and management of GPA, MPA, EGPA and PAN.