ANCA-Associated Vasculitis

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are a group of disorders including three distinct clinical variants of vasculitis characterized by inflammatory cell infiltration of the walls of small and medium-sized vessels: (1) granulomatosis with polyangiitis (GPA), (2) eosinophilic granulomatosis with polyangiitis (EGPA) and (3) microscopic polyangiitis (MPA). Mucocutaneous manifestations are frequently associated with AAV, being mainly represented by a spectrum of lesions ranging from palpable purpura, nodules, vesicles and blisters to livedo reticularis and necrotic-ulcerative lesions. Peculiar mucocutaneous findings are gangrene of the fingers or penis, pyoderma gangrenosum-like lesions, “strawberry gingivitis”, and nasal deformities with saddle nose aspect. Erythema multiforme-like lesions and erythema elevatum diutinum-like lesions are characteristically associated with EGPA and MPA, respectively. Urticaria-like lesions are found both in EGPA and MPA. Dermatopathological assessment usually shows a picture of leukocytoclastic vasculitis, with or without granulomatous changes. The aim of this chapter is to briefly review clinical features of AVV, focusing on mucocutaneous manifestations. Finally, a brief overview of differential diagnoses and management of AAV is provided.