Step 2 CK · Internal Medicine · Rheumatology

Vasculitis (Clinical)

Name: Vasculitis (Clinical)
Creator: Veli Bakalov, MD

Sort by vessel size, steroid the temporal artery before you biopsy it, and read the ANCA

Rheumatology·Vasculitis & Systemic Inflammatory Disease·4 min read·9 high-yield points·Reviewed by Veli Bakalov, MD @HemeOncBuddy

Study materialsNo account needed

Card deckActive-recall cards · quick checks · quiz

High-yield

Classify vasculitis by vessel size: large (GCA, Takayasu), medium (PAN, Kawasaki, Buerger), small (ANCA-associated GPA, MPA, EGPA; immune-complex IgA and cryoglobulinemic).
GCA: over 50 with new headache, scalp tenderness, jaw claudication, monocular vision loss and ESR often over 50; overlaps polymyalgia rheumatica.
Suspected GCA gets high-dose glucocorticoids immediately; temporal artery biopsy (long segment, skip lesions) stays positive for 1–2 weeks, and tocilizumab or upadacitinib spares steroids.
Takayasu: woman under 40 (often Asian) with absent pulses, arm BP discrepancy, bruits and claudication from aortic arch disease.
PAN: hepatitis B-associated, ANCA-negative, lung-sparing medium-vessel vasculitis with renovascular hypertension, mesenteric angina, mononeuritis multiplex and microaneurysms on angiography.
Kawasaki: child under 5 with fever for 5 days or more plus conjunctivitis, rash, cervical adenopathy, strawberry tongue and hand/foot changes; IVIG plus aspirin prevents coronary aneurysms.
c-ANCA/PR3 = GPA (sinusitis, saddle nose, cavitary nodules, RPGN); p-ANCA/MPO = MPA (no granulomas, pulmonary-renal syndrome) and EGPA (asthma, eosinophilia, cardiac deaths).
IgA vasculitis: child after a URI with palpable purpura on buttocks and legs, arthralgia, colicky abdominal pain (intussusception) and hematuria; supportive care.
Behçet: recurrent painful oral and genital ulcers, uveitis, erythema nodosum and pathergy; Silk Road, HLA-B51.

A size-based framework

Organize by vessel size. The caliber of the vessel involved predicts the clinical picture: large-vessel disease causes pulse deficits and ischemic claudication, medium-vessel disease causes organ infarcts and aneurysms, and small-vessel disease causes palpable purpura, glomerulonephritis and alveolar hemorrhage.

Vasculitis by vessel size

Size	Disorders	Typical clues
Large	Giant cell arteritis, Takayasu arteritis	Headache and vision loss, or absent pulses, bruits and limb claudication
Medium	Polyarteritis nodosa, Kawasaki disease, Buerger disease	Visceral infarcts, microaneurysms, coronary aneurysms, digital ischemia
Small, ANCA-associated	GPA, EGPA, MPA	Pauci-immune glomerulonephritis, lung involvement
Small, immune-complex	IgA vasculitis, cryoglobulinemic vasculitis	Palpable purpura, arthralgia, nephritis

Initial workup. ESR and CRP, CBC, creatinine and urinalysis with microscopy (RBC casts), ANCA, complement levels, hepatitis B and C serologies and cryoglobulins; confirm with tissue biopsy or angiography.

Large-vessel vasculitis

Giant cell (temporal) arteritis. A patient over 50 with new headache, scalp tenderness, jaw claudication and monocular visual loss from anterior ischemic optic neuropathy. ESR is high, often over 50 and sometimes over 100. GCA overlaps with polymyalgia rheumatica (proximal shoulder and hip girdle pain with morning stiffness).

GCA can cause sudden, permanent monocular blindness, an ophthalmologic emergency. Start high-dose glucocorticoids on clinical suspicion; never wait for the biopsy.

Suspect GCAover 50, headache, jaw claudication, high ESR
Start high-dose steroids nowIV pulse if vision is already affected
Temporal artery biopsywithin 1–2 weeks; long segment because of skip lesions; granulomatous inflammation with giant cells
Prevent blindness and relapseslow taper; tocilizumab (anti-IL-6) or upadacitinib (JAK inhibitor) spares steroids; methotrexate is an alternative

GCA: act before the biopsy

Why treat first. The biopsy stays positive for 1–2 weeks after steroids begin, so treatment does not spoil the diagnosis. Temporal artery ultrasound showing a "halo" is an alternative first test where expertise exists; ACR favors biopsy, while EULAR favors ultrasound. Over the long term, watch for thoracic aortic aneurysm and protect bone during prolonged steroid therapy.

Takayasu arteritis. "Pulseless disease" affects women under 40, especially Asian women, and damages the aortic arch and its branches. Findings are absent or asymmetric pulses, an arm blood-pressure discrepancy, bruits and limb claudication. ESR is elevated, CT or MR angiography shows the stenoses, and treatment is glucocorticoids.

Medium-vessel vasculitis

Polyarteritis nodosa. PAN is a necrotizing medium-vessel vasculitis associated with hepatitis B. It causes renovascular hypertension (renal arteries, not glomeruli), mesenteric angina, livedo reticularis, mononeuritis multiplex and testicular pain. Angiography shows microaneurysms with a beaded pattern. Treat with glucocorticoids, adding cyclophosphamide for severe disease. In HBV-associated PAN, give antiviral therapy with a short glucocorticoid course (often plus plasma exchange) and avoid prolonged immunosuppression.

PAN is ANCA-NEGATIVE and lung-sparing, two features that separate it from the ANCA vasculitides.

Kawasaki disease. A child under 5 with fever for 5 days or more plus CRASH and Burn: Conjunctivitis (bilateral, nonexudative), Rash, cervical Adenopathy, Strawberry tongue, and Hand and foot swelling followed by desquamation. The feared complication is coronary artery aneurysm, so obtain an echocardiogram and treat with IVIG plus aspirin, one of the few pediatric uses of aspirin. Incomplete Kawasaki disease: fever for 5 days or more with only 2 or 3 criteria (or infants with 7 days of unexplained fever) and CRP 3 mg/dL or more or ESR 40 mm/h or more calls for supplemental labs; give IVIG if 3 or more are abnormal or the echocardiogram is abnormal. If CRP and ESR are lower, reassess daily and obtain an echocardiogram if fever persists.

Buerger disease. Thromboangiitis obliterans strikes young male heavy smokers with distal limb ischemia, digital ulcers or gangrene, Raynaud phenomenon and migratory superficial thrombophlebitis. Only complete smoking cessation halts it.

Small-vessel vasculitis: the ANCA group

Shared features. ANCA-associated vasculitides cause pauci-immune (few or no immune deposits) crescentic glomerulonephritis, often with lung disease. c-ANCA (anti-PR3) marks granulomatosis with polyangiitis; p-ANCA (anti-MPO) marks microscopic polyangiitis and eosinophilic granulomatosis with polyangiitis.

The ANCA vasculitides

Feature	GPA	MPA	EGPA (Churg-Strauss)
ANCA	c-ANCA, anti-PR3	p-ANCA, anti-MPO	p-ANCA, anti-MPO
Granulomas	Yes	No	Yes, eosinophil-rich
Upper airway	Chronic sinusitis, nasal ulcers, saddle-nose deformity	Spared	Sinusitis
Lungs	Cavitary nodules, hemoptysis	Alveolar hemorrhage	Late-onset asthma
Other	Rapidly progressive GN	Pulmonary-renal syndrome with RPGN	Marked eosinophilia, mononeuritis multiplex; cardiac disease drives mortality

Anti-GBM (Goodpasture) disease also causes lung hemorrhage with RPGN but shows linear IgG along the basement membrane.

Treatment. Induce remission with high-dose glucocorticoids plus rituximab or cyclophosphamide, then maintain with rituximab or azathioprine. EGPA often responds to glucocorticoids, with the anti-IL-5 antibody mepolizumab as a steroid-sparing option.

Immune-complex vasculitis and Behçet disease

IgA vasculitis (Henoch-Schönlein purpura). A child develops, after a URI, palpable purpura on the buttocks and legs with a normal platelet count, arthralgia, colicky abdominal pain (with intussusception risk) and IgA nephropathy with hematuria. It is usually self-limited and care is supportive, but follow urinalysis and blood pressure for renal involvement.

Cryoglobulinemic vasculitis. Usually driven by hepatitis C, it causes palpable purpura, arthralgia, neuropathy and membranoproliferative glomerulonephritis, with positive RF and low C4; treating the HCV is central.

Behçet disease. Recurrent painful oral and genital ulcers, uveitis, erythema nodosum and pathergy (a pustule forming at a needle-stick site), sometimes with venous thrombosis. It is more common along the Silk Road and linked to HLA-B51. Colchicine treats mucocutaneous disease; eye and organ involvement needs systemic immunosuppression.