Clinical and histopathological spectrum of cutaneous vasculitis in rheumatoid arthritis

Summary Background Cutaneous manifestations are the most frequent, and often the initial feature of extra‐articular involvement in patients with rheumatoid vasculitis. Objectives The purpose of the study was to evaluate the clinical and histological spectrum of cutaneous vasculitis and the associated systemic involvement in patients with rheumatoid vasculitis. Methods Among 525 patients with rheumatoid arthritis, 20 tissue specimens with histologically proven cutaneous necrotizing vasculitis from 11 patients were investigated by studying the types and levels of affected vessels and related clinical features. Results Small‐vessel vasculitis identified as dermal necrotizing venulitis was found in 10 patients, clinically characterized by palpable purpura, maculopapular erythema, erythema elevatum diutinum and haemorrhagic blisters. Arteritis histologically resembling cutaneous polyarteritis nodosa, clinically characterized by subcutaneous nodules, livedo reticularis, atrophie blanche and deep ulcers was identified in four patients all with systemic complications. Coexistence of venulitis and arteritis was identified in three patients. Different cutaneous vasculitic manifestations often coexisted and recurred in the same patient. Three patients with systemic complications of mononeuritis multiplex (two of three), interstitial pulmonary fibrosis (two of three) and abdominal microaneurysms (one of three) died within 1 year of onset of the cutaneous vasculitis. Immunofluorescence demonstrated vessel wall deposition of IgM and/or complement in six of the seven patients examined. Conclusions Features of cutaneous rheumatoid vasculitis overlapping both the characteristics of cutaneous necrotizing venulitis and cutaneous polyarteritis nodosa together with coexistence of these different type of vasculitis in the same or different lesional skin account for the associated diverse cutaneous vasculitic manifestations. Although dermal venulitis (leucocytoclastic vasculitis) was the most common presentation, the presence of leucocytoclastic vasculitis in rheumatoid patients did not necessarily indicate a favourable prognosis. Associations with mononeuritis multiplex and bowel involvement had a fatal prognosis, while patients with superficial dermal venulitis without other extra‐articular involvement may follow a favourable prognosis.