ESSENTIALS OF DIAGNOSIS
Rheumatoid vasculitis usually occurs in patients with severe, long-standing, nodular, destructive rheumatoid arthritis, even though the arthritis is not always still active.
Palpable purpura, cutaneous ulcers (particularly in the malleolar region), digital infarctions, and peripheral sensory neuropathy are common manifestations.
Tissue biopsy helps confirm the diagnosis of rheumatoid vasculitis, though the diagnosis is often clear from the clinical setting. Nerve conduction studies can identify involved nerves for biopsy. Muscle biopsies should be performed simultaneously with nerve biopsies to increase the diagnostic yield of the procedure.
Rheumatoid vasculitis (RV) is a variable-vessel vasculitis that occurs most commonly in patients with long-standing rheumatoid arthritis (RA). The underlying RA is characterized by rheumatoid nodules, destructive joint disease, and high titers of rheumatoid factor. The arthritis is commonly “burnt out” at the time of onset of vasculitis, and the onset of RV is typically on the order of 10–14 years after RA diagnosis. Particular human leukocyte antigen (HLA) haplotypes (those corresponding to the “shared epitope” [Chapter 13 on RA]), male sex, and smoking constitute risk factors for RV. The diagnosis of RV should be considered in any patient with RA in whom new constitutional symptoms, skin ulcerations, serositis, digital ischemia, or symptoms of sensory or motor nerve dysfunction develop. RV resembles polyarteritis nodosa because it leads to multiorgan dysfunction in the skin, peripheral nerves, gastrointestinal tract, and other organs. Microaneurysms are not typical of RV, but cutaneous ulcerations, digital ischemia, mononeuritis multiplex, and mesenteric vasculitis are common.
Immune complex deposition and antibody-mediated destruction of endothelial cells both appear to contribute to RV. Certain HLA-DR4 alleles that predispose patients to severe RA may also heighten patients’ susceptibility to RV. Cigarette smoking increases the risk of RV and has a synergistic interaction in this regard with antibodies to cyclic citrullinated peptides (anti-CCP antibodies). However, the inciting events leading to the development of RV among patients with previously destructive arthritis are not known. Factors in addition to vasculitis (eg, diabetes mellitus, atherosclerosis, and hypertension) likely play an important adjunctive role in promoting vascular occlusion. Peripheral vascular disease has been implicated as a potential risk factor for RV, but the central issue in RV is necrotizing inflammation of blood vessels.
Dermatologic findings, the most common manifestation of RV, may include palpable purpura, cutaneous ulcers (particularly in the malleolar region), and digital infarctions (Figure 38–1).
Extensive digital necrosis in a case of severe rheumatoid vasculitis.
A peripheral sensory neuropathy is a common manifestation of RV. A mixed motor-sensory neuropathy or mononeuritis multiplex may ...