A patient with radial artery thrombosis and saphenous vein thrombosis, negative antiphospholipid antibodies—does this suggest Takayasu arteritis or Behçet disease?

Behçet Disease is More Likely Than Takayasu Arteritis

The combination of both arterial (radial artery) and venous (saphenous vein) thrombosis strongly suggests Behçet disease rather than Takayasu arteritis, as Behçet is one of only two vasculitides that characteristically involves veins, while Takayasu arteritis predominantly affects large elastic arteries without typical venous involvement. 1

Key Distinguishing Features

Vascular Pattern Differences

Behçet Disease:

• Affects both arteries AND veins—a critical distinguishing feature 1
• Venous involvement occurs in approximately one-third of patients, most commonly as superficial thrombophlebitis but also deep vein thrombosis in the vena cava and peripheral veins 1, 2, 3
• Can involve any artery or vein, large or small, systemic or pulmonary 1
• Small vessel vasculitis is the primary pathology 1

Takayasu Arteritis:

• Exclusively affects elastic arteries: the aorta and its primary/secondary branches 1
• Does NOT characteristically involve veins 1
• Predominantly affects large vessels with stenosis (53% of patients) more common than aneurysm formation (23%) 1
• Most commonly affects the descending aorta, followed by abdominal, then ascending segments 1

Clinical Context Clues

Age and Demographics:

• Takayasu arteritis: Typically diagnosed in the third decade (20s), affects women 10:1 over men, onset usually before age 40 1
• Behçet disease: Can occur at various ages, more common in young men with early onset having higher risk of severe disease 2, 4

Geographic Prevalence:

• Behçet disease: Extremely common in Turkey (80-370 per 100,000), rare in United States (1-3 per million) 1, 3
• Takayasu arteritis: Rate of 2.6 cases per million in United States, with Asian overrepresentation 1

Diagnostic Workup Algorithm

Essential Clinical Features to Assess

For Behçet Disease (International Criteria):

1. Recurrent oral aphthous ulcers (mandatory criterion) 1, 2
2. Plus at least 2 of:
   • Recurrent genital ulceration (examine for scars) 1, 2, 3
   • Uveitis or retinal vasculitis (requires complete ophthalmologic exam) 1, 2
   • Skin lesions: erythema nodosum, pseudofolliculitis, or positive pathergy test 1, 2

For Takayasu Arteritis (American College of Rheumatology Criteria—need 3 of 6):

1. Age of onset <40 years 1
2. Intermittent claudication 1
3. Diminished brachial artery pulse 1
4. Blood pressure difference >10 mmHg between arms 1
5. Subclavian artery or aortic bruit 1
6. Angiographic evidence of aorta or branch vessel stenosis 1

Laboratory Evaluation

Inflammatory Markers:

• ESR and CRP elevated in ~70% of Takayasu patients in acute phase, 50% in chronic phase 1
• Can monitor disease activity in both conditions but are not specific 2

Antiphospholipid Antibodies:

• Negative aPL antibodies do NOT exclude either diagnosis 5, 6, 7
• aPL antibodies can be present in both Behçet disease (significantly elevated prevalence of aCL and anti-β2-GPI) 8, 9 and rarely in Takayasu arteritis 5, 6, 7
• The absence of aPL antibodies in your patient is therefore not diagnostically helpful

Imaging Strategy

Initial Imaging (for both conditions):

• CT angiography of chest and abdomen to evaluate thoracic aorta and branch vessels for aneurysm or occlusive disease 1
• CTA is 95% sensitive and 100% specific for Takayasu arteritis, outperforming catheter angiography 1
• CTA is valuable for Behçet disease to assess extent of vascular involvement, stenoses, aneurysms, and wall thickening 1

Advanced Imaging if Needed:

• FDG-PET/CT can detect active vascular inflammation (sensitivity 60-92%, specificity 88-100%) 1
• Contrast-enhanced MRA can detect wall enhancement indicating active inflammation 1

Critical Management Differences

If Behçet Disease is Confirmed:

For Vascular Involvement:

• Use immunosuppressive agents (corticosteroids combined with azathioprine, cyclophosphamide, or cyclosporine A) rather than anticoagulation for venous thrombosis 4
• Anticoagulants, antiplatelet agents, or antifibrinolytic agents should NOT be used for venous thrombosis in Behçet disease due to bleeding risk, especially with coexisting pulmonary arterial aneurysms 3, 4
• For arterial aneurysms: cyclophosphamide combined with corticosteroids 4

If Takayasu Arteritis is Confirmed:

Medical Management:

• Prednisone 40-60 mg daily to normalize ESR/CRP 1
• Therapy required for 1-2 years; nearly half relapse during tapering requiring additional immunosuppression (methotrexate, azathioprine, anti-TNF agents) 1
• Elective revascularization should be delayed until acute inflammation is treated and quiescent 1

Common Pitfalls to Avoid

1. Do not assume negative antiphospholipid antibodies exclude either diagnosis—both conditions can have positive or negative aPL antibodies [5-7]

2. Do not anticoagulate presumed venous thrombosis without confirming the diagnosis—if Behçet disease, anticoagulation is contraindicated and immunosuppression is the correct treatment 3, 4

3. Do not miss the mucocutaneous features of Behçet disease—perform thorough genital examination for ulcers or scars and ask specifically about recurrent oral ulcers 2

4. Do not overlook ocular involvement—complete ophthalmologic examination is mandatory as posterior uveitis can lead to blindness if untreated 2, 4

5. In Behçet disease with CNS involvement, never use cyclosporine A due to significant neurotoxicity risk 3, 4