Behçet Syndrome

Behçet syndrome is a multisystem, chronic inflammatory disease that is usually characterized by oral ulcers, genital ulcers, and uveitis. It is categorized as a variable vessel vasculitis when vasculitis is found to be present (Chapel Hill, 2012).

Epidemiology

• Incidence – 1-2/100,000 in U.S.
• Age – 20-40 years
  • Rare in children or  individuals >50 years
• Sex – M>F in Mediterranean populations; M<F in Asian and U.S. populations
  • Young males tend to have the most severe disease
• Ethnicity – rare in the U. S.
  • Much higher incidence in Mediterranean and Middle Eastern populations

Genetics

• HLA-B51 strongly associated with disease
  • Frequently expressed in individuals who live along the Silk Route (Mediterranean to Far East)
    • Association between HLA-B51 and Behçet syndrome not established outside of the Silk Route
  • Associated with severe disease manifestations, including posterior uveitis or progressive central nervous system disease

Risk Factors

• Genetics
  • HLA-B51
• Environmental exposures
  • Infections – streptococcal antigens
  • Smoking

Pathophysiology

• Vascular injury to arteries and veins of all sizes – exact cause unknown
  • Small vessel disease most common
  • Venous involvement may present as thromboembolic disease
  • Arterial aneurysms
• Abnormal cellular immune responses and lymphocyte functions

Clinical Presentation

• Disease severity varies
  • Middle Eastern countries – disease most severe in young men with severe uveitis common
  • U.S. – disease most severe in women and uveitis less common
• Constitutional – fever, fatigue, malaise
• Mucocutaneous – recurrent oral (aphthous ulcers) and genital ulcers (most common sign)
  • Must recur >3 times/year to meet International Study Group Criteria (1990)
• Musculoskeletal – peripheral arthritis, myositis, enthesitis
• Neurologic – headache, confusion, strokes, personality changes, dementia (rare), aseptic meningitis, papilledema, dural sinus thrombosis, parenchymal brain disease
• Dermatologic – erythema nodosum, papulopustular lesions, acneiform nodules, pathergy (rare in U.S.), superficial thrombophlebitis, leukocytoclastic vasculitis, pyoderma granulosum
• Gastrointestinal – ulcers predominate in ileum and colon, emesis, diarrhea
• Ophthalmologic – anterior/posterior uveitis (bilateral disease common), hypopyon, retinal scars
• Otorhinologic – paranasal sinus disease
• Bronchopulmonary – aneurysms of arteries in the lungs
• Cardiac – pericarditis, myocarditis, valvular disease
• Vascular – deep venous thrombosis, Budd-Chiari, arterial aneurysm