Vasculitides

Vasculitides are a heterogeneous group of rare autoimmune diseases characterized by blood vessel inflammation (vasculitis). Inflammation can lead to ischemia, necrosis, and/or hemorrhage, with subsequent end-organ damage. Vasculitides are either primary (idiopathic) or secondary to an underlying disease (e.g., HBV infection, cancer, systemic lupus erythematosus) or drug use. Vasculitides are further classified based on the size of the affected vessels: small-, medium-, or large-vessel vasculitis, or variable vessel vasculitis. Diagnosing vasculitides is often challenging, as symptoms are usually nonspecific; vasculitides should be considered in patients presenting with constitutional symptoms and signs of multisystem disease (e.g., palpable purpura, pulmonary infiltrates, unexplained ischemic events). Laboratory studies, imaging, and histopathology are often required to confirm the diagnosis. Management should involve a multidisciplinary team (e.g., rheumatology, ophthalmology, neurology) and aims to promptly prevent the progression of vascular inflammation with immunosuppressive therapy to avoid organ damage and death. Treatment of the underlying cause (e.g., with antiviral drugs) and/or symptomatic management (e.g., with NSAIDs) is often necessary.

Etiology ^[1]

• Primary (idiopathic)
• Secondary to another disease or drug use, e.g.:
  • Infectious diseases
    • Viral infection: e.g., HBV, HCV, HIV
    • Infectious endocarditis
    • Tuberculosis
    • Syphilis
  • Drugs: e.g., hydralazine, cocaine
  • Malignancy: e.g., multiple myeloma, lymphoproliferative disorders
  • Autoimmune diseases: e.g., systemic lupus erythematosus (SLE), Sjogren syndrome, sarcoidosis, IBD

Classification ^[2]

• Based on the 2012 Chapel Hill Consensus Nomenclature
• Classification is based on the size of the vessel predominantly affected:
  • Large-vessel vasculitis
  • Medium-vessel vasculitis
  • Small-vessel vasculitis
    • ANCA-associated vasculitis of small vessels
    • Non-ANCA-associated vasculitis of small vessels
  • Variable vessel vasculitis

Approach to management ^[1]

Vasculitis should be suspected in patients with constitutional symptoms and multisystemic inflammatory disease. Specific manifestations depend on the vessels affected.

• Tailor the approach to the suspected disease and/or affected organ or system.
• Rule out other (more common) diagnoses (e.g., infections, cancer, other autoimmune diseases).
• Assess for secondary causes of vasculitis (see “Etiology”).
• Consult a rheumatologist and/or other specialists as required.
• Start management based on disease severity and the affected organ or system.

Most patients with vasculitis present with nonspecific features (e.g., constitutional symptoms, elevated inflammatory markers).

Initial evaluation

• Perform a thorough history and physical examination; ≥ 1 of the following clinical features are usually found in patients with vasculitis :
  • Typical cutaneous lesions (e.g., palpable purpura, livedo reticularis, digital gangrene)
  • Pulmonary-renal syndromes (e.g., asthma, hemoptysis, glomerulonephritis)
  • Limb claudication, asymmetric pulses and/or blood pressure measurements, bruits
  • Temporal headache, visual loss, mononeuritis multiplex
• Findings suggestive of vasculitis on routine studies include:
  • CBC: anemia of chronic disease, thrombocytosis, eosinophilia
  • Inflammatory markers: ↑ ESR, ↑ CRP
  • Infectious diseases workup: positive hepatitis B testing or hepatitis C testing
  • Autoimmune diseases workup: negative ANAs and aPL antibodies
  • Chest x-ray: lung involvement (e.g., ground glass opacity, nodular lesions)

Vasculitis has a wide variety of signs and symptoms; there is no single typical presentation.

Additional evaluation

Consider further diagnostics guided by clinical suspicion to:

• Determine the extent of the disease, e.g.:
  • Urine studies and chest CT to evaluate for kidney and lung involvement
  • Nerve conduction studies, electromyography, and creatine kinase levels
• Establish the type of vasculitis: e.g., ↓ ANCAs and ↑ cryoglobulins indicates cryoglobulinemic vasculitis
• Confirm the diagnosis: with imaging (e.g., MRA, CTA) or histological studies

Management

• Immunosuppressive therapy is generally indicated.
• Surgical therapy may be required in specific cases (e.g., those with limb ischemia).
• Supportive care
  • Provide pain management.
  • Prevent complications of glucocorticoid therapy.
  • Monitor adverse effects of immunosuppressants.
  • Consider PCP prophylaxis.

ANCA-associated small-vessel vasculitis

Granulomatosis with polyangiitis is the 'C' disease: Curvy nose (saddle nose deformity), Chronic sinusitis, Cough, Conjunctivitis and Corneal ulceration, Cardiac arrhythmias, non-Caseating granulomas on biopsy, cANCA, Corticosteroids and Cyclophosphamide as treatment.

Non-ANCA-associated small-vessel vasculitis

• Infectious diseases
• Thrombotic disorders, e.g.:
  • Antiphospholipid syndrome
  • Thrombotic thrombocytopenic purpura
  • Sickle cell disease
• Thromboangiitis obliterans
• Amyloidosis
• Scurvy
• Ergotamines

The differential diagnoses listed here are not exhaustive.