Blood vessel inflammation is a central feature of rheumatoid arthritis (RA). Synovial membrane inflammation is characterized histologically by mononuclear cell cuffing of postcapillary venules. In addition, vascular inflammation is considered the primary event in the formation of rheumatoid nodules . In nodule formation, small-vessel vasculitis leads to fibrinoid necrosis that forms the core of the lesion, surrounded by fibroblastic proliferation.
In contrast to this type of blood vessel inflammation, however, the term “rheumatoid vasculitis” (RV) refers specifically to a protean, destructive inflammatory process that is centered on the blood vessel wall itself and that is associated with substantial morbidity. RV may affect a wide range of blood vessel types, from medium-sized muscular arteries to somewhat smaller arterioles to post-capillary venules. Within a given patient, clinical features of both medium- and small-vessel disease may be found. RV leads to necrosis, to blood vessel occlusion, and to tissue ischemia in a manner that resembles other forms of systemic vasculitis, particularly polyarteritis nodosa. (See "Clinical manifestations and diagnosis of polyarteritis nodosa".)
This topic will review the clinical features of RV and the ways in which the diagnosis is established. The epidemiology, pathophysiology, and treatment of RV are presented separately. (See "Epidemiology and pathogenesis of rheumatoid vasculitis" and "Treatment of rheumatoid vasculitis".)
RV typically occurs in patients with longstanding, joint-destructive RA. In one study, the mean duration between the diagnosis of RA and the onset of vasculitic symptoms was 13.6 years . Presentations of RV within five years of the RA diagnosis are very unusual. Patients with RV nearly always have rheumatoid nodules (picture 1) and are typically strongly positive for rheumatoid factor . RV usually develops at a time when the inflammatory arthritis is “burned out” (ie, when the erosive process that led to joint destruction has become less active). At such times, unfortunately, patients who have already incurred considerable morbidity from RA and its therapies require intensive, potentially toxic treatments more than ever.
The areas of the body involved most commonly by RV are the skin, digits, peripheral nerves, eyes, and heart. The most devastating form of RV is characterized by a medium-sized vasculitis reminiscent of (and histologically identical to) polyarteritis nodosa. Many of the clinical manifestations of RV reflect this predilection for medium-sized vessels, even though purpura, petechiae, and papules (manifestations of small-vessel involvement) may also occur.