Learning Objectives
Systematically classify Vasculitides by vessel size and immunologic markers. Differentiate between ANCA-associated and immune-complex mediated small-vessel disease, and identify the critical multisystem triads required for USMLE-style diagnosis.
1. Large-Vessel Vasculitis
Granulomatous inflammation primarily affects the aorta and its major branches.
| Condition | Epidemiology | Clinical Presentation / Pathophysiology | High-Yield Notes |
|---|---|---|---|
| Giant Cell (Temporal) Arteritis | Females > 50 years old. | Unilateral headache, jaw claudication, and temporal tenderness. Risk of blindness. | Associated with PMR; High ESR; Treat with steroids before biopsy. |
| Takayasu Arteritis | Asian females < 40 years old. | “Pulseless disease”; weak upper extremity pulses, night sweats, fever. | Granulomatous thickening of the aortic arch and great vessels. |
2. Medium-Vessel Vasculitis
Involves muscular arteries supplying major organs; it often presents with ischemia, microaneurysms, or thrombosis.
| Condition | Epidemiology | Clinical Presentation / Pathophysiology | High-Yield Notes |
|---|---|---|---|
| Buerger Disease | Heavy smokers, males < 40. | Intermittent claudication, gangrene, Raynaud phenomenon, and autoamputation. | Segmental thrombosing vasculitis. Smoking cessation is the only treatment. |
| Kawasaki Disease | Asian children < 4 years old. | Conjunctivitis, Rash, Adenopathy, Strawberry tongue, Hand-foot edema, and fever. | Risk of coronary artery aneurysms. Treat with IVIG and Aspirin. |
| Polyarteritis Nodosa (PAN) | Middle-aged males; 30% HBV+. | Renal/Visceral ischemia, hypertension, abdominal pain, melena. Spares Lungs. | “String of pearls” on arteriogram; transmural fibrinoid necrosis. |
3. Small-Vessel Vasculitis (ANCA-Associated)
Necrotizing vasculitis typically divided by their specific ANCA serology (MPO vs. PR3).
| Category | Condition | Clinical Presentation | High-Yield Notes |
|---|---|---|---|
| p-ANCA (MPO) | Microscopic Polyangiitis | Lung, kidney, and skin involvement. Palpable purpura. | Pauci-immune glomerulonephritis; No granulomas. |
| p-ANCA (MPO) | Eosinophilic Granulomatosis (Churg-Strauss) | Asthma, peripheral neuropathy (wrist/foot drop), and eosinophilia. | Granulomatous necrotizing vasculitis; Elevated IgE. |
| c-ANCA (PR3) | Granulomatosis with Polyangiitis (Wegener) | Nasal septum perforation, hemoptysis, hematuria (triad: Upper/Lower Resp + Renal). | Focal necrotizing granulomas; Treat with Cyclophosphamide/Rituximab. |
4. Small-Vessel Vasculitis (Immune Complex Mediated)
Vessel damage caused by the deposition of circulating immune complexes (Type III Hypersensitivity).
| Condition | Etiology | Clinical Findings | High-Yield Notes |
|---|---|---|---|
| IgA Vasculitis (HSP) | Often follows URI; Most common in children. | Triad: Arthralgia, Abdominal pain, Palpable purpura on the buttocks/legs. | Secondary to IgA deposition; Associated with IgA nephropathy. |
| Mixed Cryoglobulinemia | Often, HCV viral infection. | Palpable purpura, weakness, arthralgias. | Cryoglobulins (IgG/IgM) precipitate in the cold. |
| Cutaneous Small-Vessel | Drug reaction (e.g., Penicillin, Sulfa). | Palpable purpura 7–10 days after drug use. | Leukocytoclastic vasculitis; no visceral involvement. |
5. All-Vessel Vasculitis
Conditions that can involve arteries and veins of various sizes across multiple systems.
| Condition | Epidemiology | Clinical Presentation | High-Yield Notes |
|---|---|---|---|
| Behçet Syndrome | Turkish / Eastern Mediterranean descent. | Recurrent oral and genital ulcers, uveitis, erythema nodosum. | Associated with HLA-B51; Triggered by HSV or Parvovirus. |
Activity: Vasculitis Size & Serology Quick-Fire Quiz
High-Yield Mnemonics:
- Kawasaki (CRASH): Conjunctivitis, Rash, Adenopathy, Strawberry tongue, Hand/foot changes.
- Wegener’s (C-Shape): Affects the nose, lungs, and kidneys in a “C” pattern and uses c-ANCA.
- Churg-Strauss: Think of a panting asthmatic (p-ANCA).