Vasculitis Syndromes

Vasculitis Overview - Fiery Vessels 101

• Vasculitis: Inflammation of blood vessel walls → vessel damage (stenosis, aneurysm), tissue ischemia & organ dysfunction.
• Pathogenesis: Primarily immune-mediated; also infectious, drug-induced.
• Symptoms: Systemic (fever, weight loss) + organ-specific.
• Classification by vessel size (Simplified Chapel Hill):
  • Large (LVV): Giant Cell Arteritis (GCA), Takayasu Arteritis (TAK)
  • Medium (MVV): Polyarteritis Nodosa (PAN), Kawasaki Disease
  • Small (SVV):
    • ANCA-associated (AAV): GPA (Wegener's), MPA, EGPA (Churg-Strauss)
    • Immune complex: IgA Vasculitis (HSP), Cryoglobulinemic Vasculitis

⭐ ANCA (Anti-Neutrophil Cytoplasmic Antibodies) are key diagnostic markers for AAV (e.g., GPA, MPA).

Large Vessel Vasculitis - Giant Arteries' Ail

• Affects aorta & its major branches. Characterized by granulomatous inflammation.
• Giant Cell Arteritis (GCA) / Temporal Arteritis:
  • Age > 50 years, often associated with Polymyalgia Rheumatica (PMR).
  • Symptoms: New-onset headache, jaw claudication, scalp tenderness, visual symptoms (e.g., amaurosis fugax). ⚠️ High risk of irreversible blindness.
  • Diagnosis: ↑ESR/CRP; temporal artery biopsy (gold standard) shows mononuclear infiltrate, giant cells (skip lesions common).
  • Treatment: Immediate high-dose corticosteroids (e.g., Prednisolone 40-60 mg/day).

  ⭐ GCA is the most common systemic vasculitis in adults over 50 years.

• Takayasu Arteritis ("Pulseless Disease"):
  • Typically affects women < 40 years (often Asian).
  • Symptoms: Limb claudication, bruits, absent/diminished pulses, BP discrepancy >10 mmHg between arms, systemic features (fever, malaise).
  • Diagnosis: Angiography (MRA/CTA) showing stenosis, occlusion, or aneurysms of aorta/branches.
  • Treatment: Corticosteroids, immunosuppressants (e.g., MTX, AZA), revascularization if needed.
  • 📌 Mnemonic: "Takayasu takes your pulse away" (young females).

Medium Vessel Vasculitis - Mid-Sized Miseries

• Polyarteritis Nodosa (PAN)
  • Segmental necrotizing inflammation of medium arteries.
  • Spares pulmonary arteries; HBV association (~30%).
  • Clinical: Fever, weight loss. Renal (HTN, no GN), neuropathy (mononeuritis multiplex), skin (livedo, purpura), testicular pain.
  • Biopsy: Transmural inflammation. Angiography: Microaneurysms ("rosary sign").

  ⭐ Polyarteritis Nodosa typically spares the lungs, differentiating it from ANCA-vasculitides.

• Kawasaki Disease (KD)
  • Acute febrile vasculitis, childhood (<5 yrs). Mucocutaneous Lymph Node Syndrome.
  • Fever ≥5 days + ≥4/5 CRASH criteria:
    • Conjunctivitis (bilateral, non-exudative)
    • Rash (polymorphous)
    • Adenopathy (cervical, ≥1.5 cm)
    • Strawberry tongue, lip changes
    • Hand/Foot changes (erythema/edema, desquamation) (📌 CRASH & Burn: Burn=Fever)
  • Risk: Coronary artery aneurysms.
  • Tx: IVIG + Aspirin.

Small Vessel Vasculitis - Tiny Tube Terrors

Affects arterioles, capillaries, venules.

• ANCA-Associated Vasculitides (AAV): Pauci-immune glomerulonephritis (GN).

  • Granulomatosis with Polyangiitis (GPA) (Wegener's)
    • c-ANCA/PR3-ANCA ( >80% ).
    • ENT (sinusitis, otitis, saddle nose), Lungs (nodules, DAH), Kidneys (RPGN).
    • Granulomas on biopsy.
  • Microscopic Polyangiitis (MPA)
    • p-ANCA/MPO-ANCA ( ~70% ).
    • Lungs (DAH), Kidneys (RPGN), Skin (palpable purpura). No granulomas.
  • Eosinophilic Granulomatosis with Polyangiitis (EGPA) (Churg-Strauss)
    • p-ANCA/MPO-ANCA ( ~40-60% ), marked eosinophilia ( >10% or >1500/µL ).
    • Asthma, allergic rhinitis, neuropathy (mononeuritis multiplex), cardiac, skin. Eosinophilic granulomas on biopsy.

• Immune Complex Vasculitides

  • IgA Vasculitis (Henoch-Schönlein Purpura - HSP)
    • Most common childhood vasculitis. Palpable purpura (lower limbs/buttocks), arthralgia, abdominal pain, renal (IgA nephropathy).
    • Often follows URI.
  • Cryoglobulinemic Vasculitis
    • Strongly associated with Hepatitis C (Type II & III).
    • Meltzer's triad: palpable purpura, arthralgia, weakness. ↓ Complement (C4).

⭐ GPA classically presents with a triad: upper airway (sinusitis, epistaxis), lower airway (hemoptysis, infiltrates), and renal (glomerulonephritis) involvement.

High‑Yield Points - ⚡ Biggest Takeaways

• Giant Cell Arteritis: >50 years, temporal artery biopsy, linked to polymyalgia rheumatica.
• Takayasu Arteritis: "Pulseless disease" in young females, affects aorta and its branches.
• Kawasaki Disease: Affects children, risk of coronary artery aneurysms, features CRASH & Burn.
• Polyarteritis Nodosa (PAN): Associated with Hepatitis B, spares pulmonary circulation, "rosary sign" angiography.
• GPA (Wegener's): c-ANCA (PR3-ANCA) positive, involves respiratory tract and kidneys.
• IgA Vasculitis (HSP): Common in childhood, presents with palpable purpura, arthritis, GI and renal issues.
• Behçet's Disease: Recurrent oral/genital ulcers, uveitis, positive pathergy test.