How is Behçet's disease diagnosed?

There is no test for Behçet’s disease at the moment. It is diagnosed by specific patterns of symptoms and repeated outbreaks of them.

Any other causes for these symptoms have to be ruled out first. The symptoms do not have to occur together, but can have happened at any time.

Diagnostic guidelines

There are levels of certainty for diagnosis:

International Study Group diagnostic guidelines (very strict for research purposes)
Practical clinical diagnosis (generally agreed pattern but not so strict)
‘Suspected’ or ‘Possible’ diagnosis (incomplete pattern of symptoms)

1. International Study Group strict research level guidelines for diagnosis

Must have:

• mouth ulcers (any shape,size or number at least 3 times in any 12 months)

Along with 2 out of the next 4 ‘hallmark’ symptoms:

• genital ulcers (including anal ulcers and spots in the genital region and swollen testicles or epididymitis in men)
• skin lesions (papulo-pustules, folliculitis, erythema nodosum, acne in post-adolescents not on corticosteroids)
• eye inflammation (iritis, uveitis, retinal vasculitis, cells in the vitreous)
• pathergy reaction (papule >2 mm diameter, 24-48 hrs or more after needle-prick)

2. Practical clinical guidelines for patients not included in research cohorts

Must have:

• mouth ulcers

Along with 1 out of the 4 ‘hallmark’ symptoms above

Along with 2 of the following symptoms:

• arthritis/arthralgia
• nervous system symptoms
• stomach and/or bowel inflammation
• deep vein thrombosis
• superficial thrombophlebitis
• cardiovascular problems
• inflammatory problems in chest and lungs
• problems with hearing and/or balance
• extreme exhaustion
• changes of personality, psychoses
• any other member of the family with a diagnosis of Behçet’s disease

3. 'Suspected' or 'possible' diagnosis

Usually given when someone does not have mouth ulcers or has mouth ulcers but does not have 1 of the 4 'hallmark' symptoms but has other symptoms and signs of inflammation and other causes for these have been ruled out.

Symptom proportions for members of the Behcets Syndrome Society in the UK (survey dated 1994)

Symptom	*% of people with symptom*
Mouth ulcers	100
Arthritis/arthralgia	93
Genital ulcers	89
Skin lesions	86
Eye inflammation	68
Tissue reactivity (pathergy)	32
Thrombophlebitis	32
Neurological problems	31
Inflammatory bowel disease	28
Deep vein thrombosis	22

(Other symptoms were not measured)