Common symptoms 1, oral cavity: recurrent oral mucosal ulcers, similar to recurrent aphthous ulcers. Most of them are of light or herpes-like type, and heavy type can also occur. Ulcers begin at the tip of the tongue, tongue edge, lips, cheeks, the floor of the mouth and other poor keratinization area, the number varies, the size varies, the diameter of 0.2 ~ 0.3cm, round or oval, slightly concave, the surface may have a yellow pseudomembrane, surrounded by a congested red halo, burning pain is obvious, 7 ~ 14 days can be healed by itself, generally do not leave a scar. After an interval of varying lengths, it recurs again. 2, genital: mainly for external genital ulcers, often recurrent, but the interval is much larger than oral ulcers. Ulcers are mostly found on labia majora and minora, penis, glans, scrotum, the shape is similar to oral ulcers, the diameter is larger, up to 0.5cm or so. Although the number of ulcers is small, but because the place is susceptible to infection and friction, often slower healing and severe pain. The ulcers have a tendency to heal on their own and may leave a scar. Ulcers can also occur in the vagina, cervix, involving small arteries will cause vaginal bleeding, can also cause orchitis or epididymitis, with local lymph node swelling. The incidence of genital ulcers is also high, but lower than oral ulcers. 3, skin: mainly manifested as recurrent erythema nodosum, facial folliculitis, acne-like rash, subcutaneous thrombophlebitis and skin prick reaction. The most common and typical is erythema nodosum, which mostly occurs in the limbs, especially in the lower limbs. The erythema is 1~2cm in diameter, painful to the touch, heals spontaneously after one week with hyperpigmentation and no scarring, and can reappear after 7~14 days. Skin needling reaction, also known as Koebner’s phenomenon (Koebner’s phenomenon), refers to the patient to receive intramuscular injection, within 24~48h into the needle at the place of red rash and small pus spots, intravenous injection can appear thrombophlebitis. This is caused by the peripheral blood vessels showing hypersensitivity to non-specific stimuli, and has diagnostic significance. Clinical test method is: ethanol disinfection of the skin, with a sterile needle directly into or add saline 0.1ml injected into the skin of the forearm, 24 ~ 48h after the eye of the needle appeared red rash and pus tendency that is positive for the reaction of the needle. The rate of skin damage is also high. 4, eye: eye lesions can be divided into anterior segment lesions and posterior segment lesions. Anterior segment lesions mainly include iridocyclitis, anterior chamber pus, conjunctivitis and keratitis. Posterior segment lesions are mainly choroiditis, optic nerve papillitis, optic nerve atrophy and lower body lesions, secondary cataracts, glaucoma, retinal detachment, macular degeneration, and ocular atrophy. The lesions often begin as monocular and anterior segment of the eye and later progress to bilateral and posterior segment of the eye. Repeated episodes of eye lesions can lead to gradual loss of vision and even blindness. Eye lesions are the least frequent of the common symptoms, but the consequences are serious. Rare Symptoms 1. Joints: small and large joints under the four feet and lumbosacral can be involved, but mainly involves large joints such as knees, wrists, elbows, ankles, etc. Symptoms are similar to those of rheumatoid arthritis, but without wandering, with swelling, pain, redness and heat. Easy to relapse. No deformity and osteoporosis, general X-ray examination is not abnormal. Cardiovascular system: vascular symptoms are the main feature. In the past, it was often neglected, but now there are more clinical reports. It is more common in males. (1) Veins: mainly manifested as phlebitis and venous thrombosis, occlusion. It is superficial phlebitis of the inferior saphenous vein, the anterior vena cava, and the veins of the upper limbs. Clinical manifestations of simple erythema, round or oval, a few millimeters in diameter, with mild pain, can subside by itself. And deep venous vasculitis inflammation, venous thrombosis (such as superior vena cava or other mediastinal vein thrombosis) caused by the consequences of more serious. (2) Arteries: the main manifestations of arteritis, arterial stenosis, closure and aneurysm often due to aneurysm rupture caused by severe out of grates and lead to death. Aneurysms tend to occur at the place where arterial puncture has been performed, so angiography should be avoided as much as possible in patients with BD. (3) Heart: it can be manifested as myocarditis, pericardial lesion, myocardial infarction, heart valve prolapse, heart enlargement and so on, but the lesion is rare. (3) Digestive system: clinical manifestations are mainly fever, abdominal pain, nausea, vomiting and gastrointestinal bleeding. Ileal intestinal mucosal ulcers are common, which may cause intestinal perforation and hemorrhage. Intestinal BD needs to be differentiated from Crohn’s disease. In the former, there is no abnormality in X-ray examination, but in the case of disease and longevity, barium contrast is seen as a filling defect shadow. In the latter case, oral, perineal, skin and eye symptoms as well as intestinal perforation and bleeding are rare, while systemic symptoms such as fever, emaciation and anemia are more serious. 4.Neurological system: it can be manifested as ① meningitis syndrome: headache, impaired consciousness, mental abnormality, optic nerve papillae edema, mild deviation, cervical rigidity and other meningeal irritation. ② brainstem syndrome: dizziness, headache, tinnitus, impaired consciousness, diplopia, eye tremor, eye muscle paralysis, dysphagia, mastication weakness, peripheral facial paralysis. Peripheral nerve damage syndrome: numbness, pain and weakness of limbs, sensory impairment, muscle atrophy, swelling of limbs, poor tendon reflexes. Spinal cord syndrome: bilateral lower limb numbness and weakness, incomplete paraplegia, urinary retention, impotence, segmental dysesthesia and so on. 5.Respiratory system: lung lesions are common, manifested as fever, chest pain, cough, hemoptysis. In addition, pleural effusion and hilar lymphadenopathy may also occur. 6.Urinary system: mainly nephritis, proteinuria, hematuria can occur. 7.Other rare symptoms include hyperthermia sepsis-like symptoms, nephrotic syndrome, leukemia and so on. Diagnosis: Clinical symptoms and signs are the main diagnostic basis. As BD symptoms are diverse, appear at different times, and lack of specificity, so detailed inquiry and receipt of medical history is very important, especially internal medicine, surgery, dermatology, neurology, gynecology and other aspects of the history of BD can provide important clues to the discovery of rare BD symptoms. Laboratory tests, although numerous, lack specificity and are used only for reference. Clinically, the appropriate tests can be selected according to the systems and organs involved in the symptoms. For example: blood routine, urine routine, humoral immunity, cellular immunity, fibrinolytic activity, microcirculation and blood rheology, X-ray (joints, chest radiographs, GI, etc.), electroencephalography, CT, MRI and so on. The diagnostic criteria for BD in leukoaraiosis are not standardized, and over the years there have been many different opinions. More recognized in recent years are the diagnostic criteria proposed by the 1990 International Symposium on BD based on recurrent aphthous ulcers.