What is Behçet's Disease?
Behçet's disease is a systemic vasculitis caused by dysregulated immune responses in genetically susceptible individuals, characterized by recurrent oral ulcers plus at least two additional features: genital ulcers, eye inflammation (uveitis/retinal vasculitis), or specific skin lesions. 1
Pathophysiology and Etiology
The disease results from a complex interplay between genetic predisposition (particularly HLA-B51 association) and environmental triggers that lead to profound inflammatory responses, likely triggered by infectious agents in susceptible hosts. 1, 2, 3
Neutrophil hyperactivity and T-helper 17/IL-17 pathways play central roles in the inflammatory attacks, with affected organs showing significant neutrophil and lymphocyte infiltration. 3
Geographic Distribution and Demographics
Prevalence varies dramatically by geography: Turkey has the highest rates (80-370 cases per 100,000 persons), while the United States has only 1-3 cases per million, with Mediterranean and Eastern populations most commonly affected. 1, 3
The disease typically begins in the third or fourth decade of life with roughly equal sex distribution, though young males with early onset experience more severe disease courses. 1, 3
Clinical Manifestations
Diagnostic Criteria
- Diagnosis requires oral ulceration PLUS at least two of the following: recurrent genital ulceration, uveitis/retinal vasculitis, or specific skin lesions. 1
Organ System Involvement
Mucocutaneous and Joint Disease:
- These manifestations impair quality of life but typically don't cause permanent damage and respond well to treatment. 4
- Oral and genital ulcers are hallmark features that often precede other manifestations, making their recognition crucial for early diagnosis. 3
Major Organ Involvement (Poor Prognosis):
- Ocular disease: Posterior uveitis and retinal vasculitis can cause serious damage or blindness if untreated. 5, 6
- Vascular involvement: Affects approximately one-third of patients, involving both arteries and veins, and is a major cause of mortality and morbidity, especially in young males. 1, 7
- Neurological involvement: Central nervous system manifestations require aggressive treatment and cyclosporine A must be avoided due to neurotoxicity risk. 1, 5
- Gastrointestinal involvement: Associated with poor prognosis and requires prompt aggressive treatment. 4
Disease Course and Prognosis
Behçet's disease follows a relapsing-remitting pattern, with inflammatory exacerbations that generally decrease in frequency and severity over time, allowing for treatment tapering and eventual discontinuation in many patients. 4, 5
Young men with early disease onset represent a high-risk subgroup requiring more aggressive treatment, closer follow-up, and early systemic immunosuppression. 1, 4, 5
When limited to skin, mucosa, and joints, prognosis is generally good without permanent damage, but major organ involvement (ocular, vascular, neurological, gastrointestinal) can cause serious damage or death if untreated. 5
Treatment Approach
Treatment Strategy by Severity:
Mild mucocutaneous and joint disease: Colchicine, topical corticosteroids, and NSAIDs are often sufficient. 6
Severe manifestations (posterior uveitis, retinal vasculitis, vascular, neurological, gastrointestinal involvement): Require aggressive immunosuppression with corticosteroids, azathioprine, cyclophosphamide, or TNF-α inhibitors. 1, 6
Critical Treatment Caveats:
Avoid cyclosporine A in patients with CNS involvement due to potential neurotoxicity. 1, 5
Avoid anticoagulants in Behçet's-related venous thrombosis due to bleeding risk, particularly with coexisting pulmonary arterial aneurysms. 1
Baseline immunosuppressive regimens should be kept at the lowest effective dose when managing patients with concurrent autoimmune conditions. 1
Monitoring Requirements
Regular assessment of inflammatory markers and organ-specific monitoring based on systems involved is necessary throughout the disease course. 4
Patients with ocular involvement require regular ophthalmologic examinations. 5
Continue monitoring patients with history of major organ involvement even during remission periods, as complications can occur despite symptom improvement. 4
Post-thrombotic syndrome frequently develops with recurrent deep vein thrombosis and may result in difficult-to-treat leg ulcers that persist despite overall disease improvement. 1, 5