The recurrent oral ulcers are a sine qua non for the diagnosis. The ulcers are usually painful, are round or oval, are 2 to 10 mm in diameter, are shallow or deep with a central yellowish necrotic base, are found anywhere in the oral cavity and may appear singly or in crops, which is more common. These ulcers persist for 1 to 2 weeks and subside without leaving scars. The genital ulcers resemble the oral ones, however, isolated genital ulcers are seldom indicative of Beh et s disease. While vaginal ulcers are usually painless, those on the external genitalia may be painful.
Ulcers occur elsewhere, as in the gut and on the skin.
In addition, an assortment of nonulcerative skin lesions may be present such as folliculitis, erythema nodosum, photosensitivity, an acne-like exanthem and infrequently vasculitis. Eye involvement is the most dreaded complication, since it may result in blindness. Decreased visual acuity results from inflammation, secondary glaucoma, cataracts, or vitreous hemorrhage. In addition, iritis, retinal vessel occlusions and optic neuritis can be found. The arthritis of Beh et s disease is usually intermittent, self-limited, not deforming and localized to the knees and ankles.