Vasculitis encompasses a wide spectrum of disorders which are characterised by inflammation of blood vessels. Their severity depends on the size and site of vessels affected.

Vasculitic disorders tend to be systemic rather than localised and should be considered in any unidentified multisystem disorder.

The 'typical' vasculitic picture

Patients with vasculitis most commonly present with multisystem inflammatory disease. This is often represented by pyrexia; constitutional symptoms; suspicious skin lesions such as ulcers and palpable purpura; ischemic neuropathies; and organ dysfunction. 

Vasculitis can occur at any age, however some classically present at certain ages:

  • Kawasaki disease is only seen in children.
  • Henoch-Schonlein purpura occurs mainly in children but can present in adults.
  • Microscopic polyagiitis (MPA) and Wegener's granulomatosis generally present at age 60-70.
  • Giant cell arteritis predominantly affects people aged over 50.


This article is concerned with disorders arising from immune-mediated inflammation of vascular walls, however it is also possible for vasculitis to arise as a result of infectious pathogens and indeed these infections themselves can indirectly induce an immune-mediated vasculitis. 

Immune-mediated vasculitis can result from any of the following mechanisms:

  • Immune complex deposition;
  • Antineutrophil Cytoplasmic Antibodies (ANCAs);
  • Anti-endothelial cell antibodies.


1. FBC (leucocytosis, thrombocytosis), ESR (>100), CRP (>10), U&E (?renal involvement), ANCA, ANA, RF, Complement levels (may be low due to consumption).

2. Urinalysis (?renal involvement: red blood cells and casts).

3. CXR (?pulmonary involvement).

4. Biopsy of skin lesion or involved organ.

Small vessel vasculitis

Vasculitic disorders can be subdivided according to the main size of blood vessel affected. Small vessel vasculitis affects arterioles, venules and capillaries but may also affect larger vessels.

Small vessel vasculitis is an uncommon disorder typically affecting elderly patients and predominantly affecting Caucasians.

(Henoch-Schonlein purpura: see next section)

Aetiology: Primary small vessel vasculitis has an unknown aetiology.

Prognosis: 5-Year survival is 80%. Early death is usually due to opportunistic infection. Serious complications include pulmonary haemorrhage and end-stage renal disease.


  • Initial treatment is cyclophosphamide and corticosteroids.
  • WBC needs to be monitored regularly (starting at two weekly for the first month) because of the risk of medication-related bone marrow suppression.
  • Maintenance treatment is with azathioprine and corticosteroids. It should be continued for at least 2 years.
Types of small vessel vasculitis

Henoch-Schonlein Purpura

Henoch-Schonlein purpura (HSP) is a systemic vasculitis most common in children and characterised by IgA deposition. The aetiology is unknown but it commonly follows an upper respiratory infection.  It can be mistaken for meningococcal sepsis.


  • Non-blanching Rash - typically on buttocks, lower limbs.
  • Arthralgia.
  • Gastrointestinal involvement - abdominal pain, bloody diarrhoea.
  • Glomerulonephritis.


    Diagnosis: Based on clinical symptoms and confirmed by tissue biopsy.


    • HSP is normally only requires symptomatic relief because it is self-limiting - usually resolving within about 2 months.
    • Immunosuppression when there is renal involvement or severe disease.


    Medium vessel vasculitis

    Medium vessel vasculitis affects small and medium-sized arteries but does not involve either major branches of the aorta or capillaries.

    The two key disorders are:

    1. Polyarteritis Nodosa
    2. Kawasaki disease


    Polyarteritis Nodosa

    Polyarteritis nodosa (PAN) is an uncommon disease and classically develops following a infection of hepatitis B virus (HBV) - although it is not a requirement.

    Typically patients experience weight loss, arthralgia, myalgia, mononeuritis multiplex, gastrointestinal complications (ischemia, infarction, haemorrhage, perforation), ischemic heart disease, hypertension, livedo reticularis and testicular pain.

    Renal and respiratory involvement should raise the possibility of an alternative vasculitic process.

    PAN is ANCA negative.


    • In the absence of HBV infection, immunosuppressive therapy - typically steroids.
    • More intense therapy - including cyclophosphamide - may be required in more severe disease. 


    Kawasaki disease

    Kawasaki disease (KD) is a self-limiting disorder, however if untreated, coronary-artery aneurysms can be a fairly common complication. KD is most common in Japan and is the leading cause of acquired paediatric heart disease worldwide.

    Presentation is usually preceded by several days of gastrointestinal or respiratory symptoms with or without irritability (potentially due to aseptic meningitis). Diagnostic criteria has been developed however some features of the disease are not included.

    [Abbreviated] Criteria: fever (with no other explanation) of at least 5 days PLUS 4 of 5 below:

    1. Bilateral non-purulent conjunctival injection.
    2. Changes of mucous membranes in upper respiratory tract.
    3. Polymorphous rash.
    4. Changes of the extremities - peripheral oedema or erythemia, and periungal desquamation.
    5. Cervical lymphadenopathy.


    [!]Consider the diagnosis of Kawasaki disease in any child with an unexplained febrile exanthematous illness - particularly if persisting >4 days.

    Management: aspirin and intravenous immunoglobulin. Relapse can occur.

    Large vessel vasculitis

    Large vessel vasculitis is characterised by inflammation of the aorta and its major branches.

    The two main large vessel vasculitides are:

    1. Giant cell arteritis; and
    2. Takayasu's arteritis.



    • Takayasu's arteritis: arteriography.
    • Giant cell arteritis: arterial biopsy.



    Giant cell arteritis (GCA) has a predilection for the extra-cranial branches of the carotid artery, with the temporal arteries being commonly affected. 

    GCA is the commonest vasculitis. It occurs more frequently in women and usually occurs in patients aged over 50.

    American College of Rheumatology (ACR) criteria for GCA diagnosis, 3/5 needed:

    • Onset at age 50 or over
    • New-onset localised headache
    • Temporal artery tenderness or decreased pulsation
    • ESR of at least 50 mm/hr
    • Abnormal artery biopsy.

    (A helpful tip is to remember the number 50!)



    • Headache and scalp pain - tenderness exacerbated by combing hair or lying on a pillow.
    • Jaw and tongue claudication. 
    • Visual loss (serious complication). 
    • Neurological complications if involvement of internal carotid or vertebral arteries. 
    • Constitutional symptoms (lethargy, malaise, fever, wt loss).
    • Musculoskeletal: symptoms of polymyalgia rheumatica; peripheral non-erosive arthritis.



    Takayasu's arteritis (TA) results in stenoses, occlusion, dilatation and aneurysm formation.

    TA has a mean onset of age at 30 and is more common in asian persons.

    The progression of TA is usually from an inflammatory phase (systemic symptoms) to development of ischemic symptoms.

    American College of Rheumatology (ACR) criteria for TA diagnosis, 3/6 needed:

    • Onset at age 40 or younger
    • Claudication of extremities
    • Decreased pulsation in brachial artery
    • Difference of at least 10 mmHg in SBP between two arms
    • Bruit over subclavian artery or abdominal aorta
    • Arteriographic evidence of narrowing or occlusion of entire aorta, primary branches or large arteries of upper or lower extremities.



    • Constitutional symptoms (lethargy, malaise, fever, wt loss) are common in the early phase of TA.
    • Vascular symptoms typically develop as the disease progresses.
    • Neurological complications if involvement of internal carotid or vertebral arteries. 



    • High-dose steroids - prednisolone up to 1 mg/kg/d. Symptoms usually reduce within 24-72h.
    • Management of cardiovascular disease risk factors.



      Autoimmune rheumatic disorders. Medicine, February 2010; 38:2.

      Robbins Basic Pathology. Kumar et al. 8th Edition.


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