Skin ulcer presentation of Wegener's granulomatosis

Cutaneous Manifestations of ANCA-Associated Small Vessels Vasculitis

Skin lesions are frequent manifestations of underlying systemic conditions, including systemic autoimmune vasculitis. In particular, anti-neutrophil cytoplasmic antibodies (ANCA) are associated with distinct forms of vasculitis characterized by inflammatory cell infiltration of the walls of small and medium-sized vessels leading to vascular destruction and tissue necrosis. ANCA-associated vasculitis is rare and systemic diseases, which can be classified based on different distribution of vascular inflammation and presence or absence of granulomatosis and asthma. Despite their diversities, ANCA-associated vasculitis, namely microscopic polyangiitis, granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis, can all display a broad variety of cutaneous manifestations, which can appear during the course of the disease or even as first sign at the time of onset. Different skin manifestations might coexist in the same patient and occur in different occasions during the course of the vasculitis. Thus, a deep knowledge of the spectrum of skin lesions as part of ANCA-associated vasculitis is mandatory for a correct diagnostic process, whenever cutaneous vasculitis is suspected. Due to this broad variety of manifestations, the diagnosis of skin involvement in ANCA-associated vasculitis is very challenging and it must be supported by a detailed medical history, accurate physical examination, specific histopathological analysis of skin biopsy and the presence of ANCA serology. In this review, we focus on the cutaneous manifestations that can develop in the context of ANCA-associated vasculitis, detailing the clinical features, the histopathological aspects as well as the direct immunofluorescence studies for each of the three conditions. Moreover, we acknowledged the differential diagnoses that must be ruled out in the diagnostic process and the main therapeutic approaches available for treatment of ANCA-associated vasculitis.

Pyoderma gangrenosum-like ulcerations in granulomatosis with polyangiitis: two cases and literature review

Granulomatosis with polyangiitis (GPA) is a systemic necrotizing small vessel vasculitis associated with circulating anti-neutrophil cytoplasmic antibodies (ANCAs). Skin manifestations, mostly represented by palpable purpura, papulonodular lesions and livedo reticularis, are present in up to 50% of the cases. Ulcerations with undermined, raised erythematous-violaceous border resembling pyoderma gangrenosum (PG) have rarely been reported as skin involvement in GPA. The presence of circulating ANCAs with a cytoplasmic labelling pattern, the involvement of internal organs, particularly of the lung, and the absence on histology of a mainly neutrophilic infiltrate in early phases of the cutaneous lesions may be regarded as clues to rule out true PG and confirm the diagnosis of GPA skin ulcerations simulating PG. Herein, we describe two paradigmatic cases of such a unique presentation of GPA and a literature review focusing on clinicopathological features of GPA presenting with PG-like ulcerations in the skin has been provided. Moreover, referring to the scenario observed in these two cases, an easy-to-use working approach for the differential diagnosis between the two conditions has also been proposed.