Behcet's syndrome is a complex multisystem disorder associated with presumed autoimmune-mediated inflammation of the arteries and veins. The precise aetiology has yet to be elucidated however. The classic triad of symptoms are oral ulcers, genital ulcers and anterior uveitis


  • Incidence: 1.00 cases per 100,000 person-years
  • Peak incidence: 30-40 years
  • Sex ratio: 1:1
Condition Relative
Genital herpes300.00
Behcet's syndrome1
Takayasu's arteritis0.26
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+


  • more common in the eastern Mediterranean (e.g. Turkey)
  • more common in men (complicated gender distribution which varies according to country. Overall, Behcet's is considered to be more common and more severe in men)
  • tends to affect young adults (e.g. 20 - 40 years old)
  • associated with HLA B51, a split antigen of HLA B5
  • around 30% of patients have a positive family history

Clinical features

  • classically: 1) oral ulcers 2) genital ulcers 3) anterior uveitis
  • thrombophlebitis and deep vein thrombosis
  • arthritis
  • neurological involvement (e.g. aseptic meningitis)
  • GI: abdo pain, diarrhoea, colitis
  • erythema nodosum


  • no definitive test
  • diagnosis based on clinical findings
  • positive pathergy test is suggestive (puncture site following needle prick becomes inflamed with small pustule forming)