Skip to Content

Behçet Disease

(Behçet's Disease)


Alexandra Villa-Forte

, MD, MPH, Cleveland Clinic

Last full review/revision June 2019 by Alexandra Villa-Forte, MD, MPH

Behçet disease is chronic blood vessel inflammation (vasculitis) that can cause painful mouth and genital sores, skin lesions, and eye problems. The joints, nervous system, and digestive tract may also become inflamed.

  • Typically, sores appear, disappear, and reappear in the mouth and on the genitals and skin.
  • Doctors base the diagnosis on established criteria.
  • Treatment depends on the areas affected but typically involves corticosteroids and sometimes other drugs that suppress the immune system.

(See also Overview of Vasculitis.)

Behçet disease occurs worldwide but is most common in the area along the silk route from the Mediterranean to China. It is relatively uncommon in the United States. It occurs nearly equally in men and women, typically beginning during the 20s, but tends to be more severe in men. Occasionally, the syndrome develops in children. The cause of Behçet disease is unknown. The risk appears to be higher in people who have certain genetic characteristics, such as people who have a gene called HLA-B51.


Almost everyone with this disease has recurring, painful mouth sores, similar to severe canker sores (recurrent aphthous stomatitis). Mouth sores are usually the first symptom of Behçet disease. Sores may appear anywhere in the mouth, such as on the tongue, gums, and lining of the mouth, and often occur in clusters. The sores are round or oval, less than half an inch to about 4 inches (about 1 to 10 centimeters) in diameter, and shallow or deep with a yellowish center. The sores last 1 to 2 weeks.

Although other kinds of mouth sores are very common (for example, cold sores caused by the herpes simplex virus), the sores caused by Behçet disease tend to last longer and be more severe.

Mouth and Genital Sores in Behçet Disease

Mouth sores (left) are usually the first symptom of Behçet disease. Sores may also appear on the genital organs (right).

© Springer Science+Business Media

Sores may also appear on the genital organs. Sores on the penis, scrotum, or vulva tend to be painful. Sores in the vagina may be painless.

Erythema Nodosum in Behçet Disease

Erythema nodosum (red bumps under the skin) can occur in people who have Behçet disease.

© Springer Science+Business Media

People may have a fever and a general feeling of illness (malaise). Other symptoms appear days to years later:

  • Eyes: The eyes are affected in 25 to 75% of people. Part of the eye becomes inflamed intermittently. This inflammation (relapsing iridocyclitis or uveitis) causes eye pain, redness, sensitivity to light, and hazy vision. Several other eye problems can occur. If untreated, blindness can develop.
  • Skin: Skin blisters and pus-filled pimples develop in about 80% of people. A slight injury, even a puncture from a hypodermic needle, can cause small red or pus-filled bumps to form. Painful reddish-purple bumps called erythema nodosum may occur on the legs.
  • Joints: In about half of affected people, the knees and other large joints become painful. This relatively mild inflammation (arthritis) does not progress or damage tissue.
  • Blood vessels: Inflammation of blood vessels (vasculitis) throughout the body can cause blood clots to form in the arteries and bulges (aneurysms) to develop in weakened blood vessel walls. Vasculitis can result in strokes if arteries to the brain are affected. It can cause kidney damage if arteries to the kidneys are affected. If arteries in the lungs are affected, bleeding may occur, and people may cough up blood.
  • Digestive tract: Symptoms may include discomfort and pain in the abdomen, cramping, diarrhea, and sores in the intestines. Symptoms may be similar to those caused by inflammatory bowel disease (Crohn disease and ulcerative colitis).
  • Central nervous system: Inflammation of the brain or spinal cord is less common but has serious consequences. People may have a headache first. Other symptoms include a fever and stiff neck (symptoms of meningitis), confusion, and loss of coordination. Changes in personality and memory loss may develop years later.


  • Established criteria
  • Blood tests

No laboratory tests can confirm Behçet disease, but doctors can base the diagnosis on an established set of criteria. Doctors suspect the disorder in people, particularly young adults, who have had 3 episodes of mouth sores in 1 year and 2 of the following criteria:

  • Recurring genital sores
  • Characteristic eye problems
  • Skin lesions that look like bumps under the skin, acne, or ulcers
  • Skin bumps or blisters triggered by a slight injury

However, symptoms may resemble those of many other disorders, including reactive arthritis (previously called Reiter syndrome), lupus (systemic lupus erythematosus), Crohn disease, herpes, and ulcerative colitis. The diagnosis may take months to make because doctors look for a pattern of symptoms that subside (called remission) and return (called relapse) to help identify the syndrome. Mouth sores can resemble other, more common sores, such as fever blisters (caused by the herpes simplex virus).

Blood tests are done. They cannot identify the disease but can confirm that inflammation is present.

The diagnosis of Behçet disease is difficult to confirm when people have only mouth sores and possibly sores on their genitals or skin. The diagnosis is much easier to make when other symptoms, such as inflammation of the eyes or blood vessels, are present.


Symptoms can come and go unpredictably, becoming very disruptive. Symptoms or symptom-free periods (remissions) may last weeks, years, or decades. Many people eventually go into remission. Occasionally, damage to the nervous system, digestive tract, or blood vessels is fatal. The risk of death is highest for young men and people with disease of the arteries or a high number of flare-ups. With time, the disease seems to quiet down.


  • Corticosteroids and other immunosuppressants
  • Other drugs, depending on symptoms

There is no cure, but treatment of Behçet disease can usually relieve specific symptoms. Which drugs are used depends on which organ is affected and how severe the disease is. For example, the following may be used:

  • For inflamed eyes and skin sores: A corticosteroid (used to reduce inflammation) can be applied to the eyes or skin. Azathioprine (a drug that suppresses the immune system [immunosuppressant]) helps preserve sharpness of vision, prevents new eye sores from forming and help existing sores heal. Methotrexate taken by mouth can hep reduce eye inflammation. Interferon alfa and tumor necrosis factor (TNF)–inhibiting drugs given by injection can help people who have eye problems.
  • For severe inflammation of the eyes or nervous system: The immunosuppressant cyclosporine may be used when eye inflammation is severe or when the corticosteroid prednisone does not adequately control symptoms.
  • For mouth and genital sores and joint pain: Corticosteroid creams, local anesthetic preparations, and sucralfate can be applied to the sores. Colchicine (used to treat gout) can be taken by mouth to prevent new sores and can reduce joint pain. Dapsone is taken by mouth and may decrease the number of mouth and genital sores and decrease how long they last. Thalidomide is taken by mouth and may help mouth, genital, and skin sores heal, but the sores may return when the drug is stopped. Azathioprine is taken by mouth and also can help heal mouth and genital sores and reduce joint pain. Etanercept, which is a tumor necrosis factor inhibitor (and thus suppresses the immune system), helps prevent new mouth sores. It is given by injection. Sometimes another tumor necrosis factor inhibitor (infliximab or possibly adalimumab) is used instead of etanercept. Interferon alfa can also be given by injection if colchicine does not help. Apremilast can be used to decrease the pain and number of mouth sores.

Cyclophosphamide and chlorambucil are used when other drugs are ineffective or when life-threatening or serious eye or nervous system complications develop.

More Information

  • American College of Rheumatology
  • National Heart, Lung, and Blood Institute
  • Vasculitis Foundation

Drugs Mentioned In This Article

Generic Name Select Brand Names
Cyclophosphamide CYTOXAN (LYOPHILIZED)
chlorambucil LEUKERAN
Azathioprine IMURAN
Methotrexate OTREXUP
Thalidomide THALOMID
infliximab REMICADE
Apremilast OTEZLA
Colchicine COLCRYS
prednisone RAYOS
sucralfate CARAFATE
adalimumab HUMIRA
Etanercept ENBREL
Dapsone ACZONE
