Vasculitis

Vasculitis is a group of medical disorders characterised by the destruction of blood vessels due to inflammation, affecting both arteries and veins. It is primarily caused by the migration of leukocytes and the resultant damage. While inflammation of veins (phlebitis) or arteries (arteritis) can occur independently, they are distinct entities from vasculitis.

Signs and Symptoms

Vasculitis presents with a variety of signs and symptoms depending on the organs affected. General symptoms include fever, unintentional weight loss, and tiredness. Skin manifestations often include palpable purpura and livedo reticularis. Muscles and joints may show signs of pain or inflammation. Neurological symptoms can range from mononeuritis multiplex to stroke, headache, tinnitus, and visual disturbances.

Cardiovascular involvement may lead to heart attacks, high blood pressure, gangrene, and palpitations. Respiratory symptoms can include nosebleeds, bloody cough, and lung infiltrates. Gastrointestinal symptoms may involve abdominal pain, bloody stools, and perforations. Kidney involvement typically manifests as inflammation of the glomeruli. Ear and nose symptoms can include sinus and ear infections, and hearing loss.

Causes

The aetiology of vasculitis is multifactorial. Infections can cause vasculitic syndromes through immune-mediated secondary events. Autoimmune responses, characterised by dysregulated immune activity, are common causes. Other factors include vascular thrombosis, which can lead to chronic vasculitic syndromes.

Classification

Primary Systemic Vasculitis

Primary systemic vasculitis is classified based on the size of the involved vessels:

• Large Vessel Vasculitis (LVV): Affects the aorta and its major branches. Examples include Takayasu arteritis (TA) and giant cell arteritis (GCA).
• Medium Vessel Vasculitis (MVV): Primarily affects medium-sized arteries. The main types are polyarteritis nodosa (PAN) and Kawasaki disease (KD).
• Small Vessel Vasculitis (SVV): Includes immune complex SVV and ANCA-associated vasculitis (AAV). AAV is necrotising and involves small vessels with few immune deposits, further classified into eosinophilic granulomatosis with polyangiitis (EGPA), granulomatosis with polyangiitis (GPA), and microscopic polyangiitis (MPA). Immune complex SVV includes normocomplementaemic urticarial vasculitis, cryoglobulinaemic vasculitis, IgA vasculitis, and anti-glomerular basement membrane disease.
• Variable Vessel Vasculitis (VVV): Affects vessels of all sizes and types. Examples are Behcet's disease (BD) and Cogan's syndrome (CS).

Secondary Vasculitis

Secondary vasculitis results from underlying conditions like systemic diseases, cancer, drug exposure, and infections. It is frequently associated with hepatitis B and C, HIV, infective endocarditis, and tuberculosis.

Single-Organ Vasculitis

Single-organ vasculitis is limited to one organ or organ system, such as the gastrointestinal tract, skin, or peripheral nerves.

Diagnosis

Diagnosis involves laboratory tests revealing signs of inflammation, such as increased ESR, elevated CRP, anaemia, leukocytosis, and eosinophilia. ANCA levels may also be elevated. Organ function tests vary based on the organs involved. A biopsy of the affected tissue is definitive for diagnosis, showing the pattern of blood vessel inflammation.

Leukocytoclasis, seen as palpable purpura, is notable in hypersensitivity vasculitis and cutaneous small-vessel vasculitis. Angiograms and FDG-PET/CT scans are useful imaging tools, especially for large vessel vasculitis. Sudden onset in children may indicate purpura fulminans, often linked to severe infection.

Treatment

Treatment focuses on reducing inflammation and suppressing the immune system. Corticosteroids like prednisone are commonly used. Additional immunosuppressive medications, such as cyclophosphamide, may be necessary. In cases of infection, antimicrobials like cephalexin are prescribed. Affected organs may require specific treatments to maintain function during the disease's active phase.

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Self-assessment MCQs (single best answer)

Which of the following is a common skin manifestation of vasculitis?

What type of vasculitis primarily affects the aorta and its major branches?

Which of the following is NOT a general symptom of vasculitis?

What is the primary cause of vasculitis?

Which laboratory test is commonly elevated in patients with vasculitis?

Which type of vasculitis is associated with ANCA (Anti-neutrophil cytoplasmic antibodies)?

Which imaging modality is particularly useful for diagnosing large vessel vasculitis?

What is the primary treatment approach for vasculitis?

Which vasculitis type includes Takayasu arteritis and giant cell arteritis?

Which of the following is a symptom of kidney involvement in vasculitis?