U01.07.055 Vasculitides

Vasculitides are a group of disorders characterized by inflammation of blood vessels, leading to ischemia and organ damage. They are classified based on the size of the vessels affected: large-, medium-, and small-vessel vasculitis.

Classification of Vasculitides

Type	Disease	Epidemiology	Clinical Features	Pathology	Diagnostic Markers	Treatment
Large-Vessel Vasculitis	Giant Cell (Temporal) Arteritis	Elderly females	– Unilateral headache – Temporal artery tenderness – Jaw claudication – May cause blindness (ophthalmic artery occlusion) – Associated with polymyalgia rheumatica	Focal granulomatous inflammation	↑ ESR	High-dose corticosteroids before biopsy
	Takayasu Arteritis	Asian females < 40 years old	– “Pulseless disease” (weak upper extremity pulses) – Fever, night sweats – Arthritis, myalgias – Skin nodules, ocular disturbances	Granulomatous thickening of aortic arch and proximal great vessels	↑ ESR	Corticosteroids
Medium-Vessel Vasculitis	Buerger Disease (Thromboangiitis Obliterans)	Heavy smokers, males < 40 years old	– Intermittent claudication – Gangrene, autoamputation of digits – Raynaud phenomenon	Segmental thrombosing vasculitis with vein and nerve involvement	None specific	Smoking cessation
	Kawasaki Disease (Mucocutaneous Lymph Node Syndrome)	Asian children < 4 years old	– Conjunctival injection – Rash (desquamating) – Adenopathy (cervical) – Strawberry tongue – Hand-foot edema – Fever (“CRASH & Burn”) – Can cause coronary artery aneurysms	Necrotizing vasculitis of medium-sized arteries	None specific	IV immunoglobulin + aspirin
	Polyarteritis Nodosa	Middle-aged men 30% Hepatitis B+	– Fever, weight loss, malaise – Abdominal pain, melena – Hypertension – Neurologic dysfunction – Cutaneous eruptions, renal damage	Transmural inflammation with fibrinoid necrosis – Renal microaneurysms (“string of pearls” on angiogram)	p-ANCA (-)	Corticosteroids + cyclophosphamide
Small-Vessel Vasculitis	Behçet Syndrome	High in Turkish & Mediterranean populations	– Recurrent aphthous ulcers – Genital ulcers – Uveitis, erythema nodosum – Flares triggered by HSV/parvovirus	Immune complex vasculitis	HLA-B51 association	Corticosteroids
	Cutaneous Small-Vessel Vasculitis	After drugs (penicillin, cephalosporins, phenytoin, allopurinol) or infections (HCV, HIV)	– Palpable purpura – No visceral involvement	Leukocytoclastic vasculitis (neutrophil infiltration)	None specific	Stop offending agent
	Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss)	History of asthma, allergic rhinitis	– Asthma – Sinusitis – Skin nodules, purpura – Peripheral neuropathy (wrist/foot drop) – Can involve heart, GI, kidneys	Necrotizing granulomatous vasculitis with eosinophilia	p-ANCA, ↑ IgE	Corticosteroids + cyclophosphamide
	Granulomatosis with Polyangiitis (Wegener’s)	Middle-aged adults	– Upper respiratory: chronic sinusitis, nasal septum perforation – Lower respiratory: hemoptysis, cough, dyspnea – Renal: hematuria, red cell casts	– Necrotizing granulomas in lung & upper airway – Necrotizing glomerulonephritis	c-ANCA (PR3-ANCA)	Corticosteroids + cyclophosphamide
	IgA Vasculitis (Henoch-Schönlein Purpura)	Children, post-URI	Triad: – Palpable purpura on buttocks/legs – Arthralgias – GI pain (risk of intussusception)	IgA immune complex deposition	Associated with IgA nephropathy (Berger’s disease)	Supportive care ± corticosteroids
	Microscopic Polyangiitis	Adults	– Similar to Granulomatosis with Polyangiitis but no nasopharyngeal involvement – Palpable purpura – Pauci-immune glomerulonephritis	Necrotizing vasculitis without granulomas	p-ANCA (MPO-ANCA)	Corticosteroids + cyclophosphamide
	Mixed Cryoglobulinemia	Often secondary to HCV infection	Triad: – Palpable purpura – Weakness – Arthralgias May also involve neuropathy, glomerulonephritis	Immune complex vasculitis (Cryoglobulin deposition)	Cryoglobulins (IgG + IgM)	Treat underlying HCV

Key Points to Remember

Large-vessel vasculitis affects the aorta and its major branches (e.g., Takayasu, Temporal Arteritis).
Medium-vessel vasculitis affects muscular arteries supplying organs (e.g., Kawasaki, Polyarteritis Nodosa).
Small-vessel vasculitis affects arterioles, capillaries, and venules (e.g., Wegener’s, Churg-Strauss, IgA vasculitis).
ANCA-associated vasculitis includes Granulomatosis with Polyangiitis (c-ANCA), Microscopic Polyangiitis (p-ANCA), and Eosinophilic Granulomatosis with Polyangiitis (p-ANCA).
Treatment varies but often includes corticosteroids and immunosuppressants (e.g., cyclophosphamide).
Vasculitis from immune complex deposition includes IgA vasculitis (Henoch-Schönlein Purpura) and Mixed Cryoglobulinemia.

Bibliography & References

Fauci AS, Kasper DL, Hauser SL, et al. Harrison’s Principles of Internal Medicine, 21st Edition.
Kumar V, Abbas AK, Aster JC. Robbins & Cotran Pathologic Basis of Disease, 10th Edition.
UpToDate. Vasculitis Syndromes Overview. Available Online.
American College of Rheumatology (ACR) Guidelines for Vasculitis.

Your voice matters – comment below!Cancel reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

USMLE Step 1 Review Series

Curriculum

U01.07.055 Vasculitides

Classification of Vasculitides

Key Points to Remember

Bibliography & References

Your voice matters – comment below!Cancel reply

Modal title