Behçet Disease Diagnostic Criteria
The International Criteria for Behçet's Disease (ICBD) from 2014 is the recommended diagnostic tool, demonstrating superior sensitivity (94.8%) compared to the older International Study Group (ISG) criteria while maintaining acceptable specificity (90.5%). 1
ICBD Scoring System (≥4 points = Behçet's Disease)
The ICBD uses a point-based system where patients scoring ≥4 points are classified as having Behçet's disease: 1
2 Points Each:
- Oral aphthosis (recurrent oral ulcers) 1
- Genital aphthosis (recurrent genital ulcers) 1
- Ocular lesions (anterior uveitis, posterior uveitis, or retinal vasculitis) 1
1 Point Each:
- Skin lesions (erythema nodosum, pseudofolliculitis, papulopustular lesions, or acneiform nodules) 1
- Vascular manifestations (arterial thrombosis, large vein thrombosis, phlebitis, or aneurysms) 1
- Central nervous system involvement (parenchymal disease or dural sinus thrombosis) 1
- Positive pathergy test (when performed—exaggerated skin response to needle prick) 1
Clinical Context and Key Features
Oral ulcers are present in virtually all patients and typically represent the first manifestation of disease. 2 These recurrent aphthous ulcers are a near-universal finding and serve as the cornerstone of diagnosis. 2
Genital ulcers occur in the majority of patients and carry significant morbidity, potentially causing obliterative scarring if inadequately treated. 2
The pathergy test, while included in the criteria, is geographically variable—it is more commonly positive in Middle Eastern and Asian populations along the ancient Silk Road. 1 In countries where ≥90% of patients undergo pathergy testing, adding this 1-point criterion increases sensitivity from 95.5% to 98.5% while maintaining specificity at 91.6%. 1
Performance Comparison: ICBD vs. ISG Criteria
The ICBD criteria substantially outperform the older ISG criteria: 1
- ICBD sensitivity: 94.8% vs. ISG sensitivity: 85.0% 1
- ICBD specificity: 90.5% vs. ISG specificity: 96.0% 1
The ICBD was developed from multinational data involving 2,556 clinically diagnosed Behçet's patients and 1,163 controls across 27 countries, making it the most extensively validated diagnostic tool. 1
Common Diagnostic Pitfalls
No pathognomonic laboratory test exists for Behçet's disease—diagnosis relies entirely on clinical manifestations using these criteria. 3, 4 This absence of a definitive biomarker makes adherence to validated criteria essential.
The ISG criteria, while highly specific (96%), miss approximately 15% of true Behçet's cases due to poor sensitivity, which can delay diagnosis and treatment of sight-threatening or life-threatening manifestations. 1
Differential diagnosis must exclude Sweet's disease, pemphigus, erythema nodosum, and Crohn's disease, as these conditions can mimic Behçet's clinical features. 4
Special Populations
For pediatric Behçet's disease, the Pediatric Behçet's Disease (PEDBD) criteria published in 2015 should be used, as disease characteristics differ substantially between children and adults. 5 However, when PEDBD criteria are unavailable, the revised ICBD demonstrates the highest sensitivity in pediatric populations, while ISG criteria remain the most specific. 5