Behçet's syndrome is classically characterized as a triad of symptoms that include recurring crops of mouth ulcers (aphthous ulcers, canker sores), genital ulcers, and inflammation of a specialized area around the pupil of the eye termed the uvea. The inflammation of the area of the eye that is around the pupil is called uveitis. Behçet's syndrome is also sometimes referred to as Behçet's disease.

The cause of Behçet's syndrome is not known. The disease is relatively rare but is more frequent and severe in patients from the Eastern Mediterranean and Asia than those of European descent. Both inherited (genetic) and environmental factors, such as microbial infections, are suspected to be factors that contribute to the development of Behçet's. Behçet's is not known to be contagious.

The symptoms of Behçet's syndrome depend on the area of the body affected. Behçet's syndrome can involve inflammation of many areas of the body. These areas include the arteries that supply blood to the body's tissues. Behçet's syndrome can also affect the veins that take the blood back to the lungs to replenish oxygen. Other areas of body that can be affected by the inflammation of Behçet's syndrome include the back of the eyes (retina), brain, joints, skin, and bowels.

The mouth and genital ulcers of Behçet's syndrome are generally painful and tend to recur in crops (many shallow ulcers occur at the same time). They range in size from a few millimeters to 20 millimeters in diameter. The mouth ulcers occur on the gums, tongue, and inner lining of the mouth. The genital ulcers occur on the scrotum and penis of males and vulva of women and can leavescars.

Inflammation of the eye, which can involve the front of the eye (uvea) causing uveitis, or the back of the eye (retina) causing retinitis, can lead to blindness. Symptoms of eye inflammation include pain, blurred vision, tearing, redness, and pain when looking at bright lights. It is very important for patients with Behçet's syndrome to have this sensitive area monitored by an eye specialist (ophthalmologist).

If the arteries become inflamed (arteritis) from Behçet's syndrome, it can lead to death of the tissues whose oxygen supply depends on these vessels. This could cause a stroke if it is affecting the brain vessels, belly pain if affecting the bowel, etc. When veins become inflamed (phlebitis), the inflammation can involve large veins that develop blood clots which can loosen and migrate to cause pulmonary embolisms.

Symptoms of inflammation of the brain or tissue that covers the brain (meninges) include headaches, neck stiffness, and is often associated with fever. Inflammation of the brain (encephalitis) and/or the meninges (meningitis) can cause damage to nervous tissue and lead to weakness or impaired function of portions of the body. This can result in confusion and coma. Typically these features occur later in the disease course, years after the diagnosis.

Joint inflammation (arthritis) can lead to swelling, stiffness, warmth, pain, and tenderness of joints with Behçet's syndrome. This occurs in about half of patients with Behçet's syndrome at sometime during their lives. Knees, wrists, ankles, and elbows are the most common joints affected. The skin of patients with Behçet's syndrome can develop areas of inflammation that spontaneously appear as raised, tender, reddish nodules (erythema nodosum), typically on the front of the legs. Some patients with Behçet's syndrome develop a peculiar red or blistery skin reaction in places where they have been pierced by blood-drawing needles (see pathergy test in diagnosis section). Research has found that acne occurs more frequently in patients with Behçet's syndrome that also have arthritis as a manifestation.

Ulcerations can occur at any location in the stomach, large or small bowel in patients with Behçet's disease.

Behçet's syndrome is diagnosed based on the finding of recurrent mouth ulcerations combined with any two of the following: eye inflammation, genital ulcerations, or skin abnormalities mentioned above.

A special skin test called a pathergy test can also suggest Behçet's syndrome. (The other criteria above are still required for ultimate diagnosis.) This test consists of pricking the skin of the forearm with a sterile needle. The test is called positive and suggests Behçet's syndrome when the puncture causes a sterile red nodule or pustule that is greater than two millimeters in diameter at 24 to 48 hours after the test.

Tests such as skin biopsy, lumbar puncture, MRI scan of the brain, and bowel tests are considered for individual patients based upon symptoms that are present.

The treatment of Behçet's syndrome depends on the severity and the location of its manifestations in an individual patient.

Steroid (cortisone) gels, pastes (such as Kenolog in Orabase) and creams can be helpful for the mouth and genital ulcers. Colchicine (Colcrys) can also minimize recurrent ulcerations. Trental (pentoxifylline) has also been used in the treatment of oral and genital ulcers.

Joint inflammation can require nonsteroidal anti-inflammatory drugs (such as ibuprofen and others) or oral steroids. Colchicine and oral and injectable cortisone are used for inflammation involving the joints, eyes, skin, and brain. Sulfasalazine (Azulfidine) has been effective in some patients for arthritis. Bowel disease is treated with oral steroids and sulfasalazine.

Diligent treatment of eye inflammation is essential. Patients with eye symptoms or a history of eye inflammation should be monitored by an ophthalmologist. Resistant eye inflammation can often respond to new biologic medications that block a protein that plays a major role in initiating inflammation, called TNF. These TNF-blocking medications, including infliximab (Remicade) and adalimumab (Humira), can also be helpful for severe mouth ulcerations.

Severe disease of the arteries, eyes, and brain can be difficult to treat and require powerful medications that suppress the immune system called immunosuppressive agents. Immunosuppressive agents used for severe Behçet's syndrome include chlorambucil (Leukeran), azathioprine (Imuran), and cyclophosphamide (Cytoxan). Cyclosporine has been used for resistant disease.

Studies suggest that thalidomide (Thalomid) may be of benefit for certain patients with Behçet's syndrome in treating and preventing ulcerations of the mouth and genitals. Side effects of thalidomide include promoting abnormal development of fetal growth, nerve injury (neuropathy), and hypersedation. Trials are currently underway evaluating interferon alpha for the treatment of eye disease in patients with Behçet's syndrome.