Cutaneous Manifestations of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

Cutaneous manifestations of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), including granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA), are poorly characterized. This report describes the dermatologic features of AAV and their association with systemic manifestations of vasculitis.

A cross-sectional study identifying and comparing the cutaneous manifestations of AAV was performed using data from a large, international, collaborative effort in order to collect comprehensive clinical data on patients with vasculitis.

Data from 1,184 patients with AAV from 130 centers worldwide were available. Cutaneous manifestations were common in all AAV subtypes: GPA (223 of 656, or 34%), MPA (85 of 302, or 28%), and EGPA (106 of 226, or 47%). The most frequent cutaneous manifestation in AAV (all types) was petechiae/purpura, which was observed in 181 patients (15%). Allergic and nonspecific manifestations, such as pruritus, urticaria, and maculopapular rash, were more common in EGPA than in other disease subtypes (all P < 0.01). Skin biopsy, while underutilized (performed in 22-44% of patients), was frequently found to be an effective test suitable for diagnosis of AAV (diagnostic in 68-94% of patients). Compared to patients without cutaneous manifestations, those with skin lesions more frequently had severe systemic manifestations of vasculitis (such as alveolar hemorrhage and glomerulonephritis), specifically patients with GPA or EGPA and cytoplasmic/anti-proteinase 3 (anti-PR3) ANCA-positive or ANCA-negative patients (hazard ratio >1.9 for all), but not those with MPA or perinuclear/antimyeloperoxidase ANCAs.

Cutaneous manifestations are common and varied in AAV and are associated with disease severity in patients with GPA, EGPA, cytoplasmic/anti-PR3 ANCA, or ANCA-negative disease. These findings underscore the potential diagnostic and prognostic importance of the cutaneous examination in the evaluation and management of AAV.