You’re in the middle of a q-bank set on hypertension and—out of nowhere—vasculitis shows up. The stem feels like a blood pressure question, but the answer choices are all different vasculitides. This is exactly where Step questions are won: not by memorizing one “buzzword,” but by knowing why each distractor doesn’t fit.
Below is a high-yield, vignette-first breakdown of Takayasu arteritis, Giant cell arteritis (GCA), Polyarteritis nodosa (PAN), and Kawasaki disease, with a focus on how they show up as hypertension + vascular disease.
The Clinical Vignette (Classic Q-Bank Style)
A 28-year-old woman presents with fatigue, low-grade fevers, and arm pain with use. She reports dizziness when she raises her arms to brush her hair. Exam shows a right arm BP 92/58 and left arm BP 124/76, with a faint right radial pulse. A subclavian bruit is heard. Labs show elevated ESR/CRP.
Question: Which diagnosis best explains her presentation?
Answer choices:
- A. Giant cell arteritis
- B. Takayasu arteritis
- C. Polyarteritis nodosa
- D. Kawasaki disease
Correct Answer: B. Takayasu Arteritis
Why it fits
This is large-vessel granulomatous vasculitis involving the aorta and its major branches, classically in a young woman (<40). The key here isn’t “vasculitis symptoms”—it’s vascular insufficiency in the upper extremities:
High-yield Takayasu clues
- Young woman, often Asian but can be any ethnicity
- Decreased pulses and blood pressure discrepancy between arms
- Bruits (subclavian, carotid)
- Limb claudication (esp. arms)
- Constitutional symptoms (fever, malaise, weight loss)
- Can cause renovascular hypertension if renal arteries involved
Path / morphology
- Granulomatous inflammation of large arteries → wall thickening, stenosis, occlusion
- “Pulseless disease” (late finding)
Boards takeaway
- If you see young woman + pulse/BP asymmetry + bruits, stop scrolling: Takayasu.
Now Kill the Distractors (Why Each One Is Wrong)
A. Giant Cell Arteritis (Temporal Arteritis) — Wrong age + wrong vascular territory
GCA is also a large-vessel granulomatous vasculitis, so it’s a tempting distractor. But the demographic and symptoms don’t match.
GCA hallmark clues
- Age ≥50 (this is non-negotiable on exams)
- New headache, scalp tenderness
- Jaw claudication (pain with chewing)
- Visual symptoms (amaurosis fugax, vision loss) due to ophthalmic artery involvement
- Polymyalgia rheumatica association (proximal muscle pain/stiffness)
- Elevated ESR/CRP
Key testing/treatment points
- Temporal artery biopsy: granulomatous inflammation with giant cells; skip lesions
- Start high-dose steroids immediately if suspected (don’t wait for biopsy) to prevent blindness
Why it’s wrong in this vignette
- Patient is 28
- Symptoms are arm claudication + BP discrepancy, not cranial ischemia
Quick rule: Young with pulse deficits → Takayasu. Older with headache/jaw claudication/vision risk → GCA.
C. Polyarteritis Nodosa (PAN) — Medium-vessel disease with renal ischemia (HTN), but not pulse asymmetry
PAN is a medium-vessel necrotizing vasculitis. It loves renal/visceral arteries and causes hypertension, which is why it’s often placed in “HTN” question sets.
PAN hallmark clues
- Systemic symptoms: fever, weight loss
- Renal ischemia → hypertension (classically without glomerulonephritis)
- Abdominal pain (mesenteric ischemia), postprandial pain
- Mononeuritis multiplex
- Livedo reticularis, nodules, ulcers
- Association with Hepatitis B (immune complex-mediated)
Boards pathology/image clue
- Transmural necrotizing inflammation of medium arteries
- Angiography: microaneurysms and “string of beads” appearance in renal/mesenteric circulation
Why PAN is wrong here
- The stem is screaming large-vessel branch disease (subclavian involvement) → BP differences between arms
- PAN doesn’t classically present with asymmetric arm pulses and subclavian bruits
Extra high-yield distinction
- PAN typically spares pulmonary circulation (a favorite “gotcha”).
D. Kawasaki Disease — Peds mucocutaneous lymph node syndrome; coronary aneurysms, not arm claudication
Kawasaki is the pediatric vasculitis that Step loves because it’s treatable and has a major complication.
Kawasaki hallmark clues
- Child <5 years
- Fever ≥5 days plus at least 4 of:
- Conjunctivitis (non-exudative)
- Rash
- Strawberry tongue / cracked lips
- Cervical lymphadenopathy
- Swollen hands/feet ± desquamation
Big complication
- Coronary artery aneurysms → thrombosis/MI in children
Treatment (high-yield)
- IVIG + aspirin
Why it’s wrong here
- Age is completely off (28-year-old)
- No mucocutaneous findings
- Presentation is chronic ischemic limb symptoms, not acute pediatric febrile illness
One Table to Rule Them All (Step-Style Comparison)
| Disease | Vessel size | Typical patient | Key clues | Major complications | High-yield treatment |
|---|---|---|---|---|---|
| Takayasu | Large | Young woman (<40) | BP discrepancy, decreased pulses, bruits, arm claudication | Aortic aneurysm, renovascular HTN | Steroids ± immunosuppressants |
| GCA | Large | Age ≥50 | Headache, scalp tenderness, jaw claudication, vision symptoms, PMR | Blindness | High-dose steroids ASAP |
| PAN | Medium | Adults; assoc. HBV | Renal ischemia → HTN, abd pain, mononeuritis multiplex, livedo | Renal failure, mesenteric ischemia, aneurysm rupture | Steroids + cyclophosphamide; treat HBV |
| Kawasaki | Medium | Child <5 | Fever ≥5 days + mucocutaneous findings | Coronary aneurysms, MI | IVIG + aspirin |
How Vasculitis Sneaks into “Hypertension & Vascular Disease” Questions
Vasculitides show up in HTN blocks for a reason: they alter renal perfusion and arterial caliber, which changes blood pressure.
Mechanisms to recognize
- Renal artery stenosis (Takayasu, PAN) → decreased renal perfusion → ↑ renin → ↑ angiotensin II → ↑ aldosterone → HTN
- Large-vessel stenosis (Takayasu) → BP discrepancies and pulse deficits that look like “vascular disease” more than inflammation
- Coronary arteritis/aneurysm (Kawasaki) → ischemia that can be tested as chest pain, arrhythmias, or MI in a child
Renin relationship (common Step framing)
- Renal hypoperfusion → ↑ renin → ↑ Ang II → ↑ aldosterone
- Expect hypokalemic metabolic alkalosis when aldosterone is driving K⁺/H⁺ loss (especially if the question layers in labs)
Rapid-Fire High-Yield “If You See X, Think Y”
- Young woman + arm claudication + BP/pulse asymmetry → Takayasu
- Older adult + headache + jaw claudication + vision risk → GCA (treat with steroids now)
- HBV + HTN + abdominal pain + mononeuritis multiplex + no lung involvement → PAN
- Child + fever + strawberry tongue + conjunctivitis + rash → Kawasaki (IVIG + aspirin)
Final Q-Bank Mindset: Why Every Answer Choice Matters
These four diseases are commonly grouped because they’re all “vasculitis,” but Step is testing whether you can localize by:
- Vessel size (large vs medium)
- Age group
- Signature ischemic territory (cranial arteries vs aortic branches vs renal/mesenteric vs coronary)
- Complication you must prevent (blindness in GCA; coronary aneurysm in Kawasaki)
When the stem gives you vascular anatomy clues (pulse deficits, bruits, BP discrepancy), prioritize those over generic inflammation symptoms. That’s how you avoid getting baited by a “granulomatous vasculitis” distractor and choose the right one.