Vasculitis: Step 1 review notes and self-test
Notes for the Vasculitis rapid review: the clue that separates each of its 7 confusion pairs, with timestamps and a self-test.
October 21, 2026
This video covers key clues that separate look-alike vasculitides and related cardiovascular conditions. Watch the video, then use these notes to test yourself.
Takayasu arteritis vs Giant cell arteritis
Takayasu arteritis affects a young patient and causes limb claudication, pulse deficits, bruits, or blood pressure asymmetry, while giant cell arteritis affects someone older than 50 and causes cranial ischemic symptoms. Do not rely on large-vessel disease alone. Use age, then separate pulse loss from headache, jaw claudication, or visual symptoms.
Takayasu arteritis vs Giant cell arteritis Both are granulomatous large-vessel vasculitides; Takayasu is young pulseless aortic-branch disease, while giant cell arteritis is older cranial ischemic disease. Open the comparison and video →Polyarteritis nodosa vs Microscopic polyangiitis
Polyarteritis nodosa is a medium-vessel disease that affects renal arteries and classically spares the lungs, while microscopic polyangiitis is a small-vessel disease that affects glomeruli and causes pulmonary-renal syndrome. Kidney disease occurs in both, so use vessel size and lung involvement to separate them. Polyarteritis nodosa may be associated with hepatitis B, while microscopic polyangiitis is associated with p-ANCA/MPO.
Polyarteritis nodosa vs Microscopic polyangiitis Polyarteritis nodosa is medium-vessel disease that classically spares lungs; microscopic polyangiitis is small-vessel pulmonary-renal disease. Open the comparison and video →Kawasaki disease vs IgA vasculitis / polyarteritis nodosa
Kawasaki disease causes at least 5 days of fever with mucocutaneous inflammation in a child under 5, while IgA vasculitis causes purpura, abdominal pain, arthralgia, and renal findings, and PAN causes systemic medium-vessel ischemia. Abdominal pain can occur in several vasculitides, so use the skin pattern, renal findings, and coronary risk to separate them.
Kawasaki disease vs IgA vasculitis / polyarteritis nodosa Kawasaki is fever plus mucocutaneous coronary-risk disease; IgA vasculitis is purpura-GI-renal disease; PAN is systemic medium-vessel ischemia. Open the comparison and video →Buerger disease vs Raynaud phenomenon
Buerger disease is tobacco-linked occlusive ischemia with ulcers, rest pain, or gangrene, while Raynaud phenomenon is episodic cold- or stress-triggered vasospasm with reversible white-blue-red color changes. Color changes can occur in both, so decide whether the symptoms reverse fully or show fixed ischemic injury.
Buerger disease vs Raynaud phenomenon Buerger disease is tobacco-linked occlusive ischemia with tissue threat; Raynaud phenomenon is episodic reversible vasospasm. Open the comparison and video →Acute infective endocarditis vs Subacute infective endocarditis
Acute infective endocarditis is abrupt, toxic, and destructive, often from Staphylococcus aureus even on normal valves, while subacute infective endocarditis develops over weeks to months, often from viridans streptococci on damaged valves. A new murmur and positive cultures can occur in both, so use the tempo, organism virulence, and valve substrate to separate them.
Acute infective endocarditis vs Subacute infective endocarditis Acute infective endocarditis is fast, toxic, and destructive; subacute infective endocarditis is slower, constitutional, and usually on damaged valves. Open the comparison and video →Hypertensive emergency vs Hypertensive urgency
Hypertensive emergency means severe blood pressure elevation with acute target-organ injury, while hypertensive urgency means severe blood pressure elevation without acute target-organ injury. Both can have blood pressure at or above 180/120 mmHg, so the number alone does not decide. Check for objective acute injury before naming the condition.
Hypertensive emergency vs Hypertensive urgency Emergency equals severe BP plus acute organ damage; urgency equals severe BP without acute organ damage. Open the comparison and video →Pulmonary arterial hypertension vs Secondary pulmonary hypertension groups
Pulmonary arterial hypertension is Group 1 pulmonary arterial vascular disease, while Groups 2 through 5 are classified by left heart disease, lung disease or hypoxia, chronic thromboembolic obstruction, or unclear or multifactorial mechanisms. Do not call every pulmonary hypertension PAH. Name the cause before naming the group.
Pulmonary arterial hypertension vs Secondary pulmonary hypertension groups Group 1 is pulmonary arterial vascular disease; Groups 2-5 are classified by the upstream cause. Open the comparison and video →Quick self-test
Name the diagnosis from the clue, then tap to check.
Child under 5 with at least 5 days of fever plus mucocutaneous inflammation: conjunctivitis, cracked lips or strawberry tongue, rash, extremity changes, and cervical lymphadenopathy.
Kawasaki disease · Kawasaki disease vs IgA vasculitis / polyarteritis nodosa
Episodic cold- or stress-triggered digital vasospasm with reversible white-blue-red color changes.
Raynaud phenomenon · Buerger disease vs Raynaud phenomenon
Abrupt fever, sepsis, and destructive valve infection, often from Staphylococcus aureus including on previously normal valves.
Acute infective endocarditis · Acute infective endocarditis vs Subacute infective endocarditis
Severe BP elevation without acute target-organ injury: no encephalopathy, stroke, chest ischemia, pulmonary edema, dissection, acute kidney injury, or vision-threatening retinopathy.
Hypertensive urgency · Hypertensive emergency vs Hypertensive urgency
Medium-vessel necrotizing vasculitis with renal artery disease, abdominal pain, neuropathy, hepatitis B association, and lung sparing.
Polyarteritis nodosa · Polyarteritis nodosa vs Microscopic polyangiitis
Small-vessel pauci-immune vasculitis with pulmonary-renal syndrome, palpable purpura, and p-ANCA/MPO association.
Microscopic polyangiitis · Polyarteritis nodosa vs Microscopic polyangiitis
Tobacco-associated inflammatory thrombosis of small and medium vessels causing distal ischemia, ulcers, rest pain, or gangrene.
Buerger disease · Buerger disease vs Raynaud phenomenon
Group 1 ____: idiopathic, heritable such as BMPR2, drug-induced, or associated PAH without left-heart, lung/hypoxia, or thromboembolic cause.
Pulmonary arterial hypertension · Pulmonary arterial hypertension vs Secondary pulmonary hypertension groups
Severe BP elevation with acute target-organ injury such as encephalopathy, stroke, MI, pulmonary edema, aortic dissection, acute kidney injury, retinopathy, or eclampsia.
Hypertensive emergency · Hypertensive emergency vs Hypertensive urgency
Patient older than 50 with new headache, scalp tenderness, jaw claudication, visual symptoms, polymyalgia rheumatica symptoms, and high inflammatory markers.
Giant cell arteritis · Takayasu arteritis vs Giant cell arteritis
Young patient, often a woman, with granulomatous large-vessel vasculitis of the aorta and major branches causing limb claudication, pulse deficits, bruits, or BP asymmetry.
Takayasu arteritis · Takayasu arteritis vs Giant cell arteritis
Indolent low-grade fever, fatigue, weight loss, and murmur over weeks to months, often from viridans streptococci on damaged valves.
Subacute infective endocarditis · Acute infective endocarditis vs Subacute infective endocarditis
Keep going
Every pair in this review has a free page in the library with a side-by-side comparison and a practice question. Work through the ones you missed in the self-test first.