This condition is far more common in males than in females (5:1 - 10:1), and usually is noted in the second or third decade of life. It is characterised by oral and genital ulceration, skin lesions and ocular lesions.

The first signal of the disease is usually oral and/or genital lesions. The oral ulcers resemble recurrent aphthous ulcers and are painful, occurring in crops. They may occur any site in the oral cavity. The ulcers may vary in size from a few millimetres up to more than a centimetre in diameter, and have an erythematous border. The ulcer bed tends to be covered in a greyish or yellowish exudate. Genital ulcers are small and found on the scrotum and root of the penis in males, and on the labia majora in females.

Ocular lesions begin as photophobia and irritation, and may range in severity.

Skin lesions appear around the genitals, on the trunk or on the limbs. They appear as small papules or pustules.

Complications include arthralgia, CNS involvement and thrombophlebitis. Cardiac or pulmonary complications may also occur.

The disease is often associated with erythema nodosum.