Vasculitis
Classification and main vasculitides
| Vasculitis | Vessels | Typical clinical presentation | Biomarkers | Induction treatment |
|---|---|---|---|---|
| Giant cell arteritis (GCA) / Temporal arteritis | Large vessels — temporal arteries + aorta + carotid branches | Female >50 years old (peak 70-80 years old) + intense unilateral temporal headaches + scalp tenderness + jaw claudication (pathognomonic) + associated polymyalgia rheumatica (50 %) | ESR >50 mm/hr (often >100) + very high CRP + anemia of inflammation + temporal artery biopsy (granulomas + giant cells) | Prednisone 40-60 mg/day IMMEDIATELY upon suspicion — DO NOT wait for biopsy + tocilizumab (Actemra® — anti-IL-6) to reduce maintenance corticosteroids |
| Takayasu's arteritis | Large vessels — aorta + its main branches | Young female (<40 years old) + asthenia + fever + limb claudication + blood pressure asymmetry + absent pulses + vascular murmur + renovascular hypertension | Elevated VS and CRP + CT angiography or MR angiography: thickening and stenosis of the aorta and its branches | Prednisone 1 mg/kg/day + methotrexate or azathioprine for steroid-sparing treatment + tocilizumab if refractory |
| Polyarteritis nodosa (PAN) | Medium-caliber vessels — muscular arteries | Peripheral neuropathy (mononeuritis multiplex ++) + livedo reticularis + subcutaneous nodules + abdominal pain (mesenteric) + renovascular hypertension + orchitis + NO glomerular involvement + HBV association (30 %) | ANCA-negative (distinguished from MPA) + visceral angiography: microaneurysms + biopsy: parietal fibrinoid necrosis | Prednisone + cyclophosphamide is severe + HBV treatment if associated (antivirals + plasmapheresis) |
| GPA - Granulomatosis with polyangiitis (Wegener's) | Small vessels + medium-caliber vessels | Triad of ENT-pulmonary-renal: chronic destructive sinusitis + crusty rhinitis + nasal septum perforation + excavated pulmonary nodules + hemoptysis + rapidly progressive glomerulonephritis (RPG) | c-ANCA (anti-PR3) positive in 80-90% of active forms + ESR + elevated CRP + creatinine + proteinuria | Corticosteroids + rituximab (Rituxan® — superior to cyclophosphamide in remission + less toxic) + or cyclophosphamide if severe form + cotrimoxazole to prevent ENT relapses |
| PAM — Microscopic polyangiitis | Small vessels — capillaries + arterioles | GNR + hémorragie alvéolaire diffuse (syndrome pneumo-rénal) + purpura + neuropathie + NO c-ANCA — p-ANCA (anti-MPO) positifs dans 60–70 % | p-ANCA (anti-MPO) +; creatinine +; proteinuria +; hematuria +; chest x-ray: alveolar opacities | Corticosteroids + rituximab + or cyclophosphamide + plasmapheresis if severe GNR |
| EGPA — Eosinophilic granulomatosis with polyangiitis (Churg-Strauss) | Small vessels | Severe refractory asthma (precedes vasculitis) + chronic rhinosinusitis + marked hypereosinophilia ++ + peripheral neuropathy + eosinophilic carditis (severe cardiac involvement) + p-ANCA positive in 40 % | Hypereosinophilia (>1,500/µL) + elevated IgE + p-ANCA (anti-MPO) 40 % + biopsy: eosinophilic granulomas | Corticosteroids + mepolizumab (anti-IL-5 — FDA + ESC 2021 approved for EGPA) + cyclophosphamide if vital organ involvement |
| Henoch-Schönlein Purpura (IgA Vasculitis) | Small vessels — IgA capillaries | Child 4–7 years old ++ + non-thrombocytopenic palpable purpura (lower limbs + buttocks) + arthralgias + abdominal pain + IgA nephropathy (hematuria + proteinuria) + often post-infectious | Elevated serum IgA + hematuria + proteinuria + skin or kidney biopsy: IgA deposits | Spontaneous resolution in 90 % of cases + NSAIDs for arthralgia + corticosteroids for severe digestive involvement + prolonged renal monitoring |
Baseline assessment for suspected vasculitis
- Standard Biology: NFS (hyper-eosinophilia + anemia + thrombocytosis) + ESR + CRP + creatinine + electrolytes + proteinuria/creatininuria + urinalysis (hematuria + casts) + liver function tests + AST + ALT + LDH
- Immunological markers: ANCA (c-ANCA anti-PR3 + p-ANCA anti-MPO) + ANA + anti-dsDNA + complement C3 + C4 + CH50 (consumed in immune complex vasculitis) + cryoglobulins + rheumatoid factor + HBV + HCV + HIV serologies
- Imaging : Chest X-ray + Chest CT + Sinus CT (GPA) + Aortic angiography CT or MRI (Aortic arch + Takayasu) + PET-CT (Large vessel vasculitis - detection of active inflammation zones)
- Histology: Temporal artery biopsy (GCA) + skin biopsy (purpura) + kidney biopsy (RPGN) + lung biopsy + neuromuscular biopsy (PAN) → essential for diagnostic confirmation in the majority of cases
Consult a doctor or rheumatologist urgently if temporal headaches, scalp tenderness, transient amaurosis, or jaw claudication appear in a person over 50 years old – these signs suggest temporal arteritis requiring immediate corticosteroids to prevent blindness. Consult the emergency room if macroscopic hematuria, acute kidney injury, hemoptysis, or febrile purpura accompany systemic inflammatory signs – these signs may indicate severe ANCA-associated vasculitis. For initial assessment and referral to rheumatology, Clinique Omicron offers consultations at its service points in Quebec and via telemedicine. To make an appointment, visit cliniqueomicron.ca.
Consult at Clinique Omicron
Clinique Omicron's physicians and nurse practitioners (NPs) discuss the diagnosis of vasculitis for unexplained systemic inflammatory conditions with multi-organ involvement, order the initial workup (ANCA + ESR + CRP + urinalysis + imaging), initiate emergency corticosteroids if temporal arteritis is suspected without waiting for a biopsy, and quickly refer to rheumatology or internal medicine for diagnostic confirmation and the initiation of immunosuppressants. Consultations are available at several clinics across Quebec and via telemedicine. To make an appointment, visit cliniqueomicron.ca.
The content of this page is for informational purposes only and does not replace the advice of a doctor or rheumatologist. In temporal arteritis, corticosteroids should be initiated immediately without waiting for a biopsy — the risk of irreversible blindness tolerates no delay. DOACs are contraindicated with mechanical prosthetic valves — this rule also applies if anticoagulation is necessary in the context of vasculitis.
Omicron Clinic
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