Behçet Syndrome

Diagnosis

Indications for Testing

  • Mucocutaneous ulcers associated with systemic symptoms

Criteria for Diagnosis

Laboratory Testing

Other Tests

  • Pathergy test – intradermal injection of skin with 20 gauge needle using normal saline
    • Positive test – demonstrates erythematous sterile papule within 48 hours

Differential Diagnosis 

Clinical Background

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 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

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
  • Abnormal cellular immune responses and lymphocyte functions

Clinical Presentation

  • 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
  • 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, superficial thrombophlebitis
  • Gastrointestinal – ulcers predominate in ileum and colon
  • Ophthalmologic – anterior/posterior uveitis (bilateral disease common), hypopyon, retinal scars
  • Otorhinologic – paranasal sinus disease
  • Bronchopulmonary – aneurysms of arteries in the lungs
  • Vascular – deep venous thrombosis

Indications for Laboratory Testing

  • Tests generally appear in the order most useful for common clinical situations
  • Click on number for test-specific information in the ARUP Laboratory Test Directory
Test Name and Number Recommended Use Limitations Follow Up
CBC with Platelet Count and Automated Differential 0040003
Method: Automated Cell Count/Differential

May help in ruling out infectious process

   
Urinalysis, Complete 0020350
Method: Reflectance Spectrophotometry/Microscopy

Screen for hematuria, proteinuria, and RBC casts

   
C-Reactive Protein 0050180
Method: Quantitative Immunoturbidimetry

Preferred test for evaluation of inflammation for suspected vasculitis

   
Anti-Neutrophil Cytoplasmic Antibody with Reflex to Titer and MPO/PR-3 Antibodies 2002068
Method: Semi-Quantitative Indirect Fluorescent Antibody/Semi-Quantitative Multiplex Bead Assay

Initial evaluation for suspected ANCA-associated vasculitis

If screen is positive, titer and MPO/PR-3 antibodies testing will be added to aid in antibody determination

   
Additional Tests Available
 
Click the plus sign to expand the table of additional tests.
Test Name and NumberComments
Sedimentation Rate, Westergren (ESR) 0040325
Method: Visual Identification

Initial evaluation for suspected vasculitis