Approach to the patient with suspected vasculitis

A vasculitis is inflammation and necrosis of a blood vessel with subsequent impairment of the circulation. It has two consequences which result in the clinical signs and symptoms:

• Vessel wall destruction leading to perforation and hemorrhage into adjacent tissues

• Endothelial injury leading to thrombosis and ischemia/infarction of dependent tissue

Characteristic features on histology

• Infiltration of the vessel wall by neutrophils, mononuclear cells, and/or giant cells

• Fibrinoid necrosis (panmural destruction of the vessel wall)

• Leukocytoclasis (dissolution of leukocytes, yielding 'nuclear dust'

Perivascular infiltration is a non-specific finding observed in a variety of disease processes. It is not considered diagnostic of vasculitis.

Mechanism of vasculitis

Vasculitis can either occur through cell-mediated process, known as granulomatous, or humoral, which are immune-mediated.

Granulomatous vasculitis

• Giant cell

• Takayasu

• Granulomatosis with polyangiitis (Wegener's granulomatosis)

• Churg-Strauss syndrome

• Isolated CNS vasculitis

Immune complex

• Polyarteritis nodosa

• Microscopic polyangitis

• Kawasaki disease

• Hypersensitivity vasculitis

• Henoch-Schonlein purpura

Categorisation of vasculitis according to vessel size

Presentation of vasculitis

There is typically not a single presentation - it may present as a rash, headache, foot-drop, vague constitutional symptoms, or a major visceral event such as stroke, bowel infarction, or alveolar hemorrhage.

Consider vasculitis in multisystem disease such as PUO or unexplained constitutional symptoms. If there is ischemic signs of symptoms. In a younger person, consider vasculitis with mononeuritis multiplex and suspicious skin lesions.

Disorders that mimic vasculitis

Large arteries

• Fibromuscular dysplasia

• Radiation fibrosis

• Neurofibromatosis

• Congenital coarctation of aorta

Medium arteries

• Ergotism

• Cholesterol emboli syndrome

• Atrial myxoma

• Lymphomatoid granulomatosis

• Thromboembolic disease

• Type IV Ehlers-Danlos

Small arteries

• Mycotic aneurysm with emboli

• Antiphospholipid syndrome

• Sepsis (gonococcal, meningococcal)

• Ecthyma gangrenosum

• Infectious endocarditis

• Thrombocytopenia

Skin lesions suggestive of vasculitis

• Palpable purpura

• Livedo reticularis (net-like rash)

• Subcutaneous nodules

• Punched-out ulcers

• Digital infarction

• Splinter hemorrhages

• Hemorrhagic macules

• Urticaria lasting >24 hours

Evaluation of suspected vasculitis

Bloods

• FBC

• CRP/ESR

  • ESR may be better in certain vasculitis

• Urinanalysis

• U+Es

  • Renal involvement

• LFTs

• Viral hepatitis panel

• Stool for blood

• Blood cultures

• ANA, RF, ANCA

• Anti-phospholipid antibodies

• Complement levels

• Infectious serologies

• CK

• Serum protein electrophoresis

Imaging

• CXR

• Echocardiography

• Angiography

Others

• Nerve conduction studies

• Tissue biopsy

• If biopsy is not feasible, angiography of certain sites may yield a diagnosis

  • Polyarteritis nodosa: Abdomen

  • Takayasu arteritis: Aortic arch

  • Buerger's disease: Extremity

  • Isolated CNS vasculitis: Brain

Angiographic features of vasculitis

1. Irregular tapering and narrowing

2. Aneurysms ('rosary beading')

General approach to treatment

1. Identify and remove inciting agents such as medications

2. Treat primary underlying disease etc antibiotics for endocarditis, interferon for Hep B and C

3. Anti-inflammatory, immunosuppression or immunotherapy tailored to extent of vasculitis. Small-vessel vasculitis confined to skin needs less aggressive treatment than systemic vasculitis involving large and/or medium sized arteries.