“Vasculitis” is a heterogeneous group of disorders characterized by inflammation within the walls of affected blood vessels. The major forms of primary systemic vasculitis are listed in Table 20–11. The first consideration in classifying cases of vasculitis is the size of the major vessels involved: large, medium, or small. The presence of the clinical signs and symptoms shown in Table 20–12 helps distinguish among these three groups. After determining the size of the major vessels involved, other issues that contribute to the classification include the following:
Does the process involve arteries, veins, or both?
What are the patient’s demographic characteristics (age, sex, ethnicity, smoking status)?
Which organs are involved?
Is there hypocomplementemia or other evidence of immune complex deposition?
Is there granulomatous inflammation on tissue biopsy?
Are antineutrophil cytoplasmic antibodies (ANCA) present?
Table 20–11.Classification scheme of primary vasculitides according to size of predominant blood vessels involved. ||Download (.pdf) Table 20–11. Classification scheme of primary vasculitides according to size of predominant blood vessels involved.
Predominantly large-vessel vasculitides
Giant cell arteritis (temporal arteritis)
Predominantly medium-vessel vasculitides
Primary angiitis of the central nervous system
Predominantly small-vessel vasculitides
Cutaneous leukocytoclastic angiitis (“hypersensitivity vasculitis”)
IgA vasculitis (Henoch-Schönlein purpura)
Hypocomplementemic urticarial vasculitis (anti-C1q vasculitis)
Granulomatosis with polyangiitis2
Eosinophilic granulomatosis with polyangiitis2
Table 20–12.Typical clinical manifestations of large-, medium-, and small-vessel involvement by vasculitis. ||Download (.pdf) Table 20–12. Typical clinical manifestations of large-, medium-, and small-vessel involvement by vasculitis.
|Large ||Medium ||Small |
|Constitutional symptoms: fever, weight loss, malaise, arthralgias/arthritis |
Asymmetric blood pressures
Absence of pulses
Cutaneous extravascular necrotizing granulomas
In addition to the disorders considered to be primary vasculitides, there are also multiple forms of vasculitis that are associated with other known underlying conditions. These “secondary” forms of vasculitis occur in the setting of chronic infections (eg, hepatitis B or C, subacute bacterial endocarditis), connective tissue disorders, inflammatory bowel disease, malignancies, and reactions to medications. Only the major primary forms of vasculitis are discussed here.
et al. One year in review 2018: systemic vasculitis. Clin Exp Rheumatol. 2018 Mar–Apr;36 Suppl 111(2):12–32.
et al. 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides. Arthritis Rheum. 2013 Jan;65(1):1–11.