Vasculitides

Overview – Vasculitides

Vasculitides refer to a diverse group of disorders characterised by inflammation of blood vessels, which can result in vessel wall damage, thrombosis, and ischaemia of downstream tissues. Vasculitis can affect vessels of any size and may present with systemic symptoms or organ-specific features depending on the vessels involved. Recognising and classifying vasculitis by vessel size is critical to guide investigations and treatment, as immune-mediated vasculitis requires immunosuppression, while infective causes require antimicrobial therapy.

Definition

Vasculitis is the inflammation of blood vessels due to immune or infective causes, leading to vessel wall necrosis, ischaemia, and possible aneurysm formation or rupture.

Large Vessel Vasculitis

Giant Cell Arteritis (Temporal Arteritis)

• Aetiology:
  • Chronic autoimmune inflammation of the temporal and ophthalmic arteries
• Epidemiology:
  • Typically affects individuals >50 years
• Pathogenesis:
  • Granulomatous inflammation leads to narrowing of affected vessels
• Clinical Features:
  • Triad: headache, jaw claudication, tender temporal arteries
  • Fever, fatigue, weight loss
  • ± Sudden painless monocular vision loss
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• Complications:
  • Untreated can lead to irreversible blindness
  • Aortic arch syndrome → aneurysm or rupture
• Investigations:
  • ↑ ESR, ↑ CRP
  • Definitive: temporal artery biopsy
  • ± Cranial angiography
• Management:
  • High-dose prednisone
  • Immunosuppressants (methotrexate, azathioprine if severe)

Medium Vessel Vasculitis

Polyarteritis Nodosa (PAN)

• Aetiology:
  • Systemic autoimmune inflammation of medium arteries
• Pathogenesis:
  • Immune complex deposition → necrosis, thrombosis, aneurysms
• Clinical Features:
  • General: fever, malaise, weight loss
  • Multisystem involvement:
    • Skin: palpable purpura, ulcers
    • Renal: hypertension
    • GI: abdominal pain, ischaemia
    • Cardiac: angina, MI
    • Neurological: peripheral neuropathy
• Investigations:
  • ↑ ESR, ↑ CRP
  • Angiogram or vascular biopsy
• Management:
  • Prednisone ± cyclophosphamide

Kawasaki Disease (Mucocutaneous Lymph Node Syndrome)

• Aetiology:
  • Most common vasculitis in children <5 years
• Risk Factors:
  • Male, Asian ethnicity
• Complications:
  • Coronary artery aneurysms
  • Myocardial infarction, arrhythmias
• Clinical Features (CRASH + Burn):
  • Conjunctivitis
  • Rash
  • Adenopathy (cervical)
  • Strawberry tongue
  • Hand-foot desquamation
  • Burn = fever >5 days
• Investigations:
  • Clinical diagnosis (4/5 CRASH + fever)
  • ECG, CXR, ECHO
  • ↑ CRP, ESR, platelets
• Management:
  • Aspirin
  • IVIG

Small Vessel Vasculitides

Granulomatosis with Polyangiitis (Wegener’s Granulomatosis)

• Aetiology:
  • Autoimmune, often c-ANCA positive
• Pathogenesis:
  • Necrotising granulomatous inflammation of nasopharynx, lungs, and kidneys
• Clinical Features:
  • Systemic: fever, rash, myalgia
  • URT: chronic sinusitis, rhinorrhoea, otitis
  • Lungs: haemoptysis, cavitating granulomas
  • Renal: glomerulonephritis
• Investigations:
  • ≥2 of ACR criteria (URTI, CXR findings, renal features, biopsy)
  • c-ANCA +
  • Biopsy: granulomatous inflammation
• Management:
  • Prednisone + cyclophosphamide or rituximab
  • ± high-dose methotrexate

Granulomatous inflammation around small vessels with epithelioid cells and giant cells.

Churg-Strauss Syndrome (Eosinophilic Granulomatosis with Polyangiitis)

• Aetiology:
  • Unknown; p-ANCA and MPO-ANCA associated
• Pathogenesis:
  • Eosinophilic granulomatous inflammation of small/medium vessels
• Clinical Features:
  • Triad: asthma, allergic rhinitis, systemic vasculitis
  • Skin nodules, purpura, myocarditis, neuropathy
• Investigations:
  • ↑ ESR, CRP, eosinophils
  • PFT: obstructive pattern
  • CXR: transient peripheral opacities
• Management:
  • Prednisone ± cyclophosphamide
  • Maintenance: methotrexate
• Prognosis:
  • Poor without treatment (5-year survival 25%)

Mixed Vessel Vasculitides

Thromboangiitis Obliterans (Buerger’s Disease)

• Aetiology:
  • Strongly associated with heavy cigarette smoking
• Pathogenesis:
  • Inflammation of small/medium arteries and veins → thrombosis, ischaemia
• Clinical Features:
  • Digital ulcers and gangrene
  • Claudication, paraesthesia
  • Raynaud’s phenomenon
• Investigations:
  • Angiogram to rule out atherosclerosis
  • Biopsy: inflammatory thrombus with sparing of vessel wall
• Management:
  • Absolute smoking cessation

Summary – Vasculitides

Vasculitides are a diverse group of inflammatory disorders affecting blood vessels of various calibres, with presentations ranging from systemic symptoms to organ-threatening ischaemia. Early recognition and classification by vessel size help tailor immunosuppressive or antimicrobial therapy. For a broader context, see our Cardiovascular Overview page.