Table 1 International Study Group diagnostic (classification) criteria for Behcet's syndrome (1990)[2]

Recurrent oral ulceration

Minor aphthous, major aphthous, or herpetiform ulceration observed by physician or patient recurring at least three times in one 12 month period

Plus two of the following

Recurrent genital ulceration

Aphthous ulceration or scarring, observed by physician or patient

Eye lesions

Anterior uveitis, posterior uveitis, cells in the vitreous on slit-lamp examination; or retinal vasculitis observed by an ophthalmologist

Skin lesions

Erythema nodosum observed by the physician or patient, pseudofolliculitis, papulopustular lesions or acneiform nodules observed by physician in post adolescent patients not on corticosteroid treatment

Pathergy

Development of a papule or pustule 24-48 hours after intradermal injection of the skin with a 20 gauge needle.

Findings applicable only in the absence of other clinical explanations