Vasculitis

🟥 LARGE VESSEL VASCULITIS

📌 Giant Cell (Temporal) Arteritis

Age: > 50 years

Vessel type: Large → medium arteries (temporal, ophthalmic, vertebral, aorta)

Key pathology

• Granulomatous inflammation

• Giant cells

• Fragmentation of internal elastic lamina

• Segmental lesions (skip areas)

Main sites

• Temporal artery

• Ophthalmic artery (⚠ blindness)

• Aorta (giant cell aortitis)

Clinical

• Headache, scalp tenderness

• Jaw claudication

• Fever, weight loss

• Visual loss (sudden, permanent)

Diagnosis

• Temporal artery biopsy (negative ≠ exclude)

Treatment

• Corticosteroids

• Anti-IL-6 if steroid-resistant

Takayasu Arteritis (Pulseless disease)

Age: < 50 years (young women)

Vessel type: Large → medium arteries (aorta & branches)

Key pathology

• Granulomatous, transmural inflammation

• Intimal hyperplasia → luminal narrowing

• Fibrosis of vessel wall

Main sites

• Aortic arch

• Great vessels

• Renal, coronary, pulmonary arteries

Clinical

• Weak/absent upper limb pulses

• BP difference between arms

• Visual disturbances

• Neurologic deficits

• Leg claudication

• HTN (renal artery involvement)

Mechanism

• T-cell mediated

🟧 MEDIUM VESSEL VASCULITIS

📌 Polyarteritis Nodosa (PAN)

Age: Adults

Vessel type: Medium ± small muscular arteries

(spares pulmonary circulation)

Association

• Hepatitis B (immune complex mediated)

Key pathology

• Segmental transmural necrotizing inflammation

• Fibrinoid necrosis

• Aneurysms & rupture

• Different stages in different vessels

Organs affected

• Kidney

• GI tract

• Heart

• Liver

Clinical

• Fever, weight loss

• Hypertension

• Abdominal pain, melena

• Peripheral neuropathy

• Myalgia

Prognosis

• Fatal if untreated

Kawasaki Disease

Age: < 5 years

Vessel type: Medium → large arteries (especially coronary)

Key pathology

• Dense transmural inflammation

• Less fibrinoid necrosis

• Intimal thickening in healed lesions

Why important?

• Coronary aneurysms → thrombosis → MI

Clinical (Mucocutaneous LN syndrome)

• Fever

• Conjunctival & oral erythema

• Strawberry tongue

• Rash

• Hand & foot edema

• Cervical lymphadenopathy

Treatment

• IVIG

• Aspirin

🟨 SMALL VESSEL VASCULITIS

📌 Microscopic Polyangiitis

Age: Adults

Vessel type: Small vessels (capillaries, arterioles, venules)

Association

• MPO-ANCA (p-ANCA)

Key pathology

• Necrotizing vasculitis

• Fibrinoid necrosis

• NO granulomas

• Leukocytoclastic vasculitis

Common organs

• Kidney (necrotizing GN – 90%)

• Lung (pulmonary capillaritis)

• Skin, GI

Clinical

• Hematuria

• Proteinuria

• Hemoptysis

• Abdominal pain

• Myalgia

📌 Granulomatosis with Polyangiitis (Wegener)

Age: ~ 40 years

Vessel type: Small → medium vessels

Association

• PR3-ANCA (c-ANCA) ≈ 95%

Classic triad

1. Upper & lower respiratory granulomas

2. Necrotizing vasculitis

3. Crescentic glomerulonephritis

Key pathology

• Necrotizing granulomas

• Geographic necrosis

Clinical

• Chronic sinusitis

• Cavitary lung nodules

• Nasal ulcers

• Hematuria

• Rash, fever, arthralgia

📌 Buerger Disease (Thromboangiitis Obliterans)

Age: < 35 years

Vessel type: Small & medium arteries + veins

Strong association

• Heavy smoking 🚬

Main sites

• Tibial & radial arteries

• Veins & nerves involved

Key pathology

• Neutrophilic vasculitis

• Microabscesses

• Segmental thrombosis

Clinical

• Claudication

• Raynaud phenomenon

• Thrombophlebitis

• Ulcers & gangrene

Treatment

• Smoking cessation ONLY