Version July 2025
INTRODUCTION —
The vasculitides are often serious and sometimes fatal diseases that require prompt recognition and therapy. Symptomatic involvement generally reflects and follows the pattern of affected organs. The distribution of affected organs may suggest a particular type of vasculitis.
The vasculitides are defined by the presence of leukocytes in vessel walls with reactive damage to mural structures. Loss of vessel integrity and occlusion of the lumen may result in downstream tissue ischemia and necrosis. In general, affected vessels vary in size, type, and location in association with the specific type of vasculitis. Vasculitis may occur as a primary process or may be secondary to another underlying disease. The exact pathogenetic mechanisms underlying these diseases are unknown.
This topic reviews the nomenclature of the different vasculitides and provides an overview of the approach to the patient with suspected vasculitis. An overview of the treatment of these disorders and detailed discussions of the individual disorders are presented separately. (See "Overview of the management of vasculitis in adults".)
MAJOR CATEGORIES OF VASCULITIS —
Classification of the noninfectious vasculitides is primarily based upon the predominant size of the vessels involved (figure 1), although there may be some overlap in the size of arteries involved with all these diseases. Thus, large-vessel vasculitis mostly affects large arteries, medium-vessel vasculitis predominantly affects medium arteries, and small-vessel vasculitis predominantly affects small arteries and capillaries. This nomenclature was reinforced by the Chapel Hill Consensus Conference (CHCC), which also recognizes that some forms of vasculitis (ie, variable-vessel vasculitis) do not involve a single predominant size of vessel (table 1).
Large-vessel vasculitis — The large vessels include the aorta and its major branches.
●Takayasu arteritis (TAK) – TAK often affects a limited portion of the large vessels, but extensive involvement such as nearly pan-aortitis can also be seen. The onset of disease usually occurs before the age of 30 years. (See "Clinical features and diagnosis of Takayasu arteritis".)
●Giant cell arteritis (GCA) – GCA, also known as temporal arteritis, has a predilection for the branches of the carotid including the superficial temporal artery. The onset of disease usually occurs in patients older than 50, with markedly increased incidence in the eighth and ninth decades of life. (See "Clinical manifestations of giant cell arteritis".)
●Other large-vessel vasculitides – There are other forms of large-vessel vasculitis that either do not have a specific name (eg, idiopathic isolated aortitis) or are part of another form of vasculitis or systemic inflammatory condition (eg, relapsing polychondritis). (See "Clinical manifestations of relapsing polychondritis", section on 'Systemic vasculitis'.)
Medium-vessel vasculitis — The medium arteries are the main visceral arteries (eg, renal, splenic, mesenteric) and their branches.
●Polyarteritis nodosa – Polyarteritis nodosa is a systemic necrotizing vasculitis that typically affects the medium- and small-sized arteries but is not associated with glomerulonephritis. (See "Clinical manifestations and diagnosis of polyarteritis nodosa in adults".)
●Kawasaki disease – Kawasaki disease is an arteritis that predominantly affects the medium and small arteries, but the aorta and large arteries may rarely be involved. The disease usually occurs in children and is often associated with a mucocutaneous lymph node syndrome. The coronary arteries may also be involved. A small number of cases have also been reported in adults [1]. (See "Kawasaki disease: Clinical features and diagnosis".)
Small-vessel vasculitis — The small vessels are intraparenchymal arteries, arterioles, capillaries, and venules. The small vessel vasculitides typically affect the skin, kidneys, and/or lungs, although organs may be involved as well.
ANCA-associated vasculitis — Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a necrotizing vasculitis that does not substantially involve the deposition of immune complexes. AAV predominantly affects small vessels and is associated with ANCA specific for myeloperoxidase (MPO-ANCA) or proteinase 3 (PR3-ANCA). Cases of ANCA-negative AAV do occur, especially in eosinophilic granulomatosis with polyangiitis (EGPA) but also to some extent in granulomatosis with polyangiitis (GPA). ANCA-negative AAV describes cases in which the patient otherwise fulfills the definition for AAV but has negative results on serologic testing for ANCA. (See "Clinical spectrum of antineutrophil cytoplasmic autoantibodies".)
The major clinicopathologic variants of AAV include microscopic polyangiitis (MPA), GPA, and EGPA; additionally, AAV can occur in only a single organ, especially a subset referred to as renal-limited AAV.
●EGPA – EGPA is an eosinophilic-rich necrotizing vasculitis predominantly affecting small- to medium-sized vessels. Patients often have chronic rhinosinusitis, asthma, and prominent peripheral blood eosinophilia. ANCA is present in approximately 40 percent of patients with EGPA, usually anti-MPO ANCA. The presence of ANCA is more frequent in patients with glomerulonephritis. (See "Epidemiology, pathogenesis, and pathology of eosinophilic granulomatosis with polyangiitis".)
●MPA – MPA is a necrotizing vasculitis that primarily affects capillaries, venules, or arterioles, most commonly manifesting as necrotizing glomerulonephritis and/or pulmonary capillaritis. Involvement of medium- and small- sized arteries may also be present. Granulomatous inflammation is usually absent. ANCA is present in >90 percent of patients with MPA. (See "Granulomatosis with polyangiitis and microscopic polyangiitis: Clinical manifestations and diagnosis".)
●GPA – GPA is a necrotizing vasculitis predominantly involving small- to medium-sized vessels (eg, capillaries, venules, arterioles, arteries, and veins). It typically produces granulomatous inflammation of the upper and lower respiratory tracts as well as necrotizing, pauci-immune glomerulonephritis. ANCA is present in >80 percent of patients with GPA. (See "Granulomatosis with polyangiitis and microscopic polyangiitis: Clinical manifestations and diagnosis".)
While MPA and GPA continue be regarded as distinct entities within AAV, they have markedly overlapping manifestations, and it can be sometimes extremely difficult to differentiate between these two diseases within a patient. Furthermore, there is a growing recognition that ANCA type (anti-MPO or anti-PR3) has more prognostic and clinical meaning rather than the disease type (MPA or GPA), leading some experts to refer to MPO-AAV or PR3-AAV, and many clinical trials in AAV now stratify enrollment by ANCA type (MPO or PR3) and report results for each subgroup [2-4].
Immune complex small-vessel vasculitis — Immune complex small-vessel vasculitis refers to vasculitis with moderate to marked vessel-wall deposits of immunoglobulin and/or complement, predominantly affecting small vessels. Glomerulonephritis is often present. Medium-sized arterial involvement is much less common in immune complex vasculitis compared with AAV.
●Cryoglobulinemic vasculitis – Cryoglobulinemic vasculitis, previously termed essential cryoglobulinemic vasculitis, is characterized by the presence of cryoglobulins, which are serum proteins that precipitate in the cold and dissolve upon rewarming. In this disorder, which is most often due to hepatitis C virus infection, cryoglobulin immune complexes are deposited in the walls of capillaries, venules, or arterioles, thereby resulting in inflammation in small vessels. Skin, glomeruli, and peripheral nerves are often involved. (See "Overview of cryoglobulins and cryoglobulinemia" and "Mixed cryoglobulinemia syndrome: Clinical manifestations and diagnosis".)
●Immunoglobulin A (IgA) vasculitis (Henoch Schönlein purpura) – IgA vasculitis is a systemic vasculitis characterized by the tissue deposition of IgA1-dominant immune complexes affecting mostly small vessels (predominantly capillaries, venules, or arterioles). IgA vasculitis typically affects the skin and gastrointestinal tract, and it often causes arthritis. A glomerulonephritis indistinguishable from IgA nephropathy may be observed. (See "IgA vasculitis (Henoch-Schönlein purpura): Clinical manifestations and diagnosis".)
●Hypocomplementemic urticarial vasculitis (HUV) – HUV is a vasculitis associated with urticaria and hypocomplementemia, and predominantly affects small vessels. Glomerulonephritis, arthritis, obstructive pulmonary disease, and ocular inflammation may also be observed. The presence of anti-C1q antibodies is one of the most distinctive findings in HUV, and consideration of the name anti-C1q vasculitis for this entity has been suggested. (See "Urticarial vasculitis", section on 'Hypocomplementemic urticarial vasculitis'.)
●Anti-glomerular basement membrane (GBM) disease – Anti-GBM disease is a vasculitis affecting glomerular capillaries, pulmonary capillaries, or both, with basement membrane deposition of anti-basement membrane autoantibodies. Lung involvement typically causes pulmonary hemorrhage, and kidney involvement causes glomerulonephritis with necrosis and crescents. (See "Anti-GBM (Goodpasture) disease: Pathogenesis, clinical manifestations, and diagnosis".)
Variable-vessel vasculitis — Variable vessel vasculitis may affect vessels of any size (ie, small, medium, and large) and type (ie, arteries, veins, and capillaries).
●Behçet syndrome – The vasculitis occurring in patients with Behçet syndrome can affect any size artery or vein. Behçet syndrome is characterized by recurrent oral and/or genital aphthous ulcers as well as cutaneous, ocular, articular, gastrointestinal, and/or central nervous system involvement. Thrombosis and arterial aneurysms can also occur. (See "Clinical manifestations and diagnosis of Behçet syndrome", section on 'Vascular disease'.)
●Cogan syndrome – Vasculitis occurring in patients with Cogan syndrome is characterized by ocular inflammatory lesions (typically interstitial keratitis) as well as inner ear disease (eg, sensorineural hearing loss and vestibular dysfunction). Vasculitis manifestations may include arteritis of any size vessel, aortitis, and aortic aneurysms. (See "Cogan syndrome".)
Single-organ vasculitis — Single-organ vasculitis refers to vasculitis in arteries or veins of any size in a single organ, and it has no features suggesting it is a limited expression of a systemic vasculitis. The involved organ and vessel type should be included in the name (eg, primary central nervous system vasculitis [CNSV], cutaneous small-vessel vasculitis [5], isolated aortitis). Some patients initially diagnosed with single-organ vasculitis may develop other disease manifestations, warranting reevaluation for another systemic vasculitis (eg, cutaneous arteritis later becoming polyarteritis nodosa).
●Primary angiitis of the central nervous system (PACNS) – PACNS, or primary CNSV, refers to vasculitis affecting the medium and small blood vessels of the brain, spinal cord, and the meninges, without systemic (nonbrain) involvement. (See "Primary angiitis of the central nervous system in adults".)
●Cutaneous small-vessel vasculitis – Cutaneous small-vessel vasculitis is defined as a single-organ, skin-isolated, small-vessel vasculitis, often leukocytoclastic, without systemic features or glomerulonephritis. (See "Overview of cutaneous small vessel vasculitis".)
Secondary vasculitides
●Vasculitis associated with rheumatic disease – Subsets of patients with systemic lupus erythematosus, rheumatoid arthritis, relapsing polychondritis, and other systemic rheumatic diseases may develop an associated vasculitis. The vasculitic process in this setting most frequently involves small muscular arteries, arterioles, and venules. (See "Systemic lupus erythematosus in adults: Clinical manifestations and diagnosis", section on 'Other associated conditions and complications' and "Clinical manifestations and diagnosis of rheumatoid vasculitis" and "Clinical manifestations of relapsing polychondritis", section on 'Systemic vasculitis'.)
●Vasculitis associated with probable etiology – Some of the vasculitides are associated with a specific etiology and the diagnosis should have a prefix specifying the underlying cause. Examples include hepatitis C virus-associated cryoglobulinemic vasculitis, hepatitis B virus-associated polyarteritis nodosa, and hydralazine-associated AAV. Hematologic and solid organ neoplasms as well as clonal B-cell lymphoproliferative disorders can also be associated with vasculitis. (See "Mixed cryoglobulinemia syndrome: Clinical manifestations and diagnosis", section on 'Infections' and "Clinical manifestations and diagnosis of polyarteritis nodosa in adults", section on 'Etiology' and "Clinical spectrum of antineutrophil cytoplasmic autoantibodies", section on 'Drug-induced ANCA-associated vasculitis'.)
DIAGNOSTIC APPROACH —
It is not possible to outline a single algorithm for evaluating patients suspected of having any one of the vasculitides because of the clinical heterogeneity of these diseases. Nevertheless, there are some elements of the medical history, physical examination, and laboratory evaluation that may be helpful when trying to identify a patient suspected of having a vasculitis. While each form of vasculitis is rare, the potential for severe organ damage or death from these diseases means it is appropriate to consider the possibility early in the evaluation of patients with any possible manifestations of vasculitis.
In general, the presence of vasculitis should be considered in patients who present with systemic or constitutional symptoms in combination with evidence of single and/or multiorgan dysfunction, and especially with some key manifestations as outlined below. The diagnosis of vasculitis is often delayed because the clinical manifestations can be mimicked by a number of other diseases.
The diagnosis of the individual vasculitides is generally based on patterns of organ injury, the size of the vessels affected, histopathologic features, and characteristic findings on diagnostic imaging. Refer to separate topic reviews for each of the individual vasculitides for a more detailed diagnostic approach once a specific type of vasculitis is suspected.
Identify evidence of systemic inflammation — Most patients with a systemic vasculitis will have symptoms or laboratory abnormalities consistent with subacute or chronic inflammation.
●Symptoms – While many symptoms (such as fever, fatigue, weight loss, and arthralgias) are often present in patients with vasculitis, these symptoms are neither sensitive nor specific for a diagnosis.
●Laboratory testing – Most forms of vasculitis are accompanied by elevation of acute phase reactants. (See "Acute phase reactants", section on 'Laboratory evaluation'.)
Identify potential organ involvement — Some forms of organ dysfunction may be more indicative of a major category of vasculitis, such as the following:
●Large-vessel vasculitis – Limb claudication, especially in the upper extremities or in a patient at low risk for atherosclerosis, may be indicative of giant cell arteritis (GCA) or Takayasu arteritis (TAK). (See "Diagnosis of giant cell arteritis", section on 'Evaluation' and "Clinical features and diagnosis of Takayasu arteritis", section on 'Diagnosis'.)
●Medium-vessel vasculitis – Acute wrist drop or foot drop due to mononeuritis multiplex and cutaneous ulcerations are features of a medium-vessel vasculitis, such as polyarteritis nodosa. However, these features may also be seen in patients categorized as having a small- or large-vessel vasculitis. (See "Clinical manifestations and diagnosis of polyarteritis nodosa in adults", section on 'Diagnosis'.)
●Small-vessel vasculitis – Glomerulonephritis, pulmonary hemorrhage, and purpura (picture 1) may be seen in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) or immune complex-mediated small-vessel vasculitis [6].
•AAV – Persistent nasal crusting, epistaxis, or upper airway disease is suggestive of granulomatosis with polyangiitis (GPA); adult-onset asthma occurs in patients with eosinophilic GPA (EGPA). (See "Granulomatosis with polyangiitis and microscopic polyangiitis: Clinical manifestations and diagnosis", section on 'Diagnosis' and "Clinical features and diagnosis of eosinophilic granulomatosis with polyangiitis (EGPA)", section on 'Evaluation'.)
Obtain confirmatory testing — After potential organ involvement has been identified, we obtain specific tests to confirm the presence of vasculitis.
Biopsy for small- and medium-vessel vasculitis — Biopsy examination of the involved tissue is essential for diagnosis of many vasculitides, but is not possible in all cases. For example, a temporal artery biopsy should be considered in cases of suspected GCA and is a generally a straightforward procedure. Similarly, skin biopsies of purpuric lesions and kidney biopsies in patients with suspected glomerulonephritis have high diagnostic yields. However, for patients with suspected TAK, except in cases where surgical repair was conducted, tissue biopsy from the aortic arch and its primary branches is not feasible, and the diagnosis is based on other clinical and radiographic findings. (See "Temporal artery biopsy technique" and "Evaluation of adults with cutaneous lesions of vasculitis", section on 'Procedure' and "The kidney biopsy".)
Vascular imaging for large-vessel vascultiis — We use magnetic resonance (MR) angiograms and computed tomography (CT) angiograms to identify the presence of vascular lesions consistent with a diagnosis of large-vessel vasculitis. Concentric arterial wall thickening, vessel wall edema, and contrast enhancement may be indicative of large-vessel vasculitis, although on their own these findings are not diagnostic. It is important to realize that no angiographic abnormalities are themselves pathognomonic for vasculitis, but they can be used to support a diagnosis when combined with other clinical data. Angiograms of mesenteric or renal arteries in polyarteritis nodosa may show aneurysms, occlusions, and vascular wall irregularities (image 1). By contrast, angiography is unlikely to be helpful in assessing a small-vessel vasculitis because the affected vessels are below the resolution of usual angiograms. (See "Clinical features and diagnosis of Takayasu arteritis", section on 'Imaging'.)
There is increasing adoption of using ultrasound to detect possible GCA, especially in countries and centers with the experience and expertise to conduct ultrasound of the temporal arteries. Positron emission tomography (PET) is sometimes useful in identifying potential inflammatory disease in the aorta and its branches. However, while more invasive imaging studies generally can be avoided, conventional catheter-based angiography remains an important diagnostic test in some situations. (See "Diagnosis of giant cell arteritis", section on 'Ultrasound with Doppler' and "Diagnosis of giant cell arteritis", section on 'Imaging modalities'.)
Consider secondary causes of vasculitis — Infection, malignancy, and other rheumatic diseases may also be associated with vasculitis and present with nonspecific evidence of inflammation. We consider these alternate diagnoses in patients who have been previously diagnosed with (or at risk for) one of these disorders and/or in patients who have features that are not commonly associated with the specific form of vasculitis under consideration.
●Large-vessel vasculitis – Syphilis and tuberculosis are uncommon causes of infectious aortitis. Connective tissue diseases, such as Ehlers-Danlos syndrome, may have angiographic changes suggestive of large vessel vasculitis, but these patients lack the systemic inflammation associated with these disorders. (See "Ehlers-Danlos syndromes: Clinical manifestations and diagnosis", section on 'Vascular EDS' and "Genetics, clinical features, and diagnosis of Marfan syndrome and related disorders", section on 'Aortic disease'.)
●Medium and small vessel vasculitis
•Exposures – A detailed history is also important to assess whether the patient has recently (up to at least some time in the prior 6 to 12 months) been exposed to specific medications or cocaine, which may be associated with drug-induced vasculitis, or has a history of hepatitis. (See "Clinical spectrum of antineutrophil cytoplasmic autoantibodies", section on 'Drug-induced ANCA-associated vasculitis' and "Clinical spectrum of antineutrophil cytoplasmic autoantibodies", section on 'Cocaine and levamisole'.)
•Concomitant diagnoses – Some rheumatic diseases, including systemic lupus erythematosus, rheumatoid arthritis, and relapsing polychondritis, may be associated with a secondary form of vasculitis. (See 'Secondary vasculitides' above.)
DIFFERENTIAL DIAGNOSIS —
Patients with nonvasculitic disease processes may present with symptoms and findings that closely mimic various vasculitides. Perhaps most common are systemic rheumatic diseases, such as systemic lupus erythematosus, atherosclerotic disease, drug reactions, and vaso-occlusive processes. Among the most important diseases to exclude are infections and malignancies, since the immunosuppressive therapy could worsen these conditions and a delay in diagnosis can be extremely dangerous. While it is beyond the scope of this review to provide a comprehensive list of all possible alternative diagnoses, we present several categories of mimics of vasculitis in a table (table 2) [7-9].
INFORMATION FOR PATIENTS —
UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.
Here is the patient education article that is relevant to this topic. We encourage you to print or e-mail this topic to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)
●Basics topics (see "Patient education: Polyarteritis nodosa (The Basics)" and "Patient education: Vasculitis (The Basics)")
●Beyond the Basics topics (see "Patient education: Vasculitis (Beyond the Basics)")
SUMMARY AND RECOMMENDATIONS
●General principles – The vasculitides are defined by the presence of leukocytes in vessel walls with reactive damage to mural structures. Loss of vessel integrity (leading to bleeding and compromise of the lumen) may result in downstream tissue ischemia and necrosis. In general, affected vessels vary in size, type, and location in association with the specific type of vasculitis. Vasculitis may occur as a primary process or may be secondary to another underlying disease. (See 'Introduction' above.)
●Nomenclature – The international Chapel Hill Consensus Conference (CHCC) has developed one of the most widely used nomenclature systems, which specifies the names and definitions for most forms of vasculitis (table 1). (See 'Major categories of vasculitis' above.)
●Major categories of vasculitis – Classification of the noninfectious vasculitides is primarily based upon the predominant size of the vessels involved (figure 1), although some overlap in the size of arteries involved occurs among the major size-based categories. There are also some forms of vasculitis that do not involve a single predominant size of vessel (variable-vessel vasculitis) (see 'Major categories of vasculitis' above). The major categories of the vasculitides include:
•Large-vessel vasculitis – Takayasu arteritis (TAK) and giant cell arteritis (GCA). (See 'Large-vessel vasculitis' above.)
•Medium-vessel vasculitis – Polyarteritis nodosa and Kawasaki disease. (See 'Medium-vessel vasculitis' above.)
•Small-vessel vasculitis – Microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), eosinophilic GPA (EGPA; Churg-Strauss), anti-glomerular basement membrane (GBM) disease, cryoglobulinemic vasculitis, immunoglobulin A (IgA) vasculitis (Henoch-Schönlein purpura), and hypocomplementemic urticarial vasculitis (anti-C1q-vasculitis). (See 'Small-vessel vasculitis' above.)
•Variable-vessel vasculitis – Behçet syndrome and Cogan syndrome. (See 'Variable-vessel vasculitis' above.)
•Single-organ vasculitis – Primary central nervous system vasculitis (CNSV). (See 'Single-organ vasculitis' above.)
•Vasculitis associated with systemic disease such as systemic lupus erythematosus, rheumatoid arthritis, and relapsing polychondritis. (See 'Secondary vasculitides' above.)
•Vasculitis associated with probable etiology such as hepatitis C virus-associated cryoglobulinemic vasculitis, hepatitis B virus-associated polyarteritis nodosa, and hydralazine-associated antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). (See 'Secondary vasculitides' above.)
●Clinical features suggestive of vasculitis – In general, the presence of vasculitis should be considered in patients who present with systemic or constitutional symptoms in combination with evidence of single and/or multiorgan dysfunction. The diagnosis of the individual vasculitides is generally based on patterns of organ injury, the size of the vessels affected, histopathologic features, and characteristic findings on diagnostic imaging. (See 'Diagnostic approach' above.)
●Diagnostic evaluation – Diagnostic evaluation for a case of possible vasculitis should include a detailed history, including drug use, infectious disease exposure, and symptoms of manifestations that may characterize or exclude a suspected diagnoses; a careful physical examination to identify potential sites of involvement of vasculitis and determine the extent of vascular lesions; general laboratory testing to help identify the degree of organ involvement and exclude another disease; additional laboratory testing, depending on the suspected diagnosis and findings; biopsy of the involved tissue if possible; and vascular imaging. (See 'Diagnostic approach' above.)
●Vasculitis mimics – Patients with nonvasculitic disease processes may present with symptoms and findings that closely mimic various vasculitides. Perhaps most common are systemic rheumatic diseases, such as systemic lupus erythematosus, atherosclerotic disease, drug reactions, and vaso-occlusive processes. Among the most important diseases to exclude are infections and malignancies since immunosuppressive therapy could worsen these conditions and a delay in diagnosis can be extremely dangerous. We present several categories of mimics of vasculitis in a table (table 2). (See 'Differential diagnosis' above.)
