Behçet disease

Other Names: Behçet's syndrome; Behçet syndrome; BD; Behcet syndrome; Behcet's disease; Behçet’s disease; Behcet's syndrome; Behçet's disease

Behçet disease is a chronic multisystem inflammatory disorder characterized by ulcers affecting the mouth and genitals, various skin lesions, and abnormalities affecting the eyes.

The signs and symptoms of Behçet disease usually begin in a person's twenties or thirties, although they can appear at any age. Some affected people have relatively mild symptoms that are limited to sores in the mouth and on the genitals. Others have more severe symptoms affecting various parts of the body, including the eyes and the vital organs. The features of Behçet disease typically come and go over a period of months or years. In most affected individuals, the health problems associated with this disorder improve with age.

Funduscopic photo left eye centered on the optic disc

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Epidemiology

Behçet disease is most common in Mediterranean countries, the Middle East, Japan, and other parts of Asia. However, it has been found in populations worldwide.

The highest prevalence of Behçet disease has been reported in northern Turkey, where the disorder affects up to 420 in 100,000 people. The disorder is rare in northern European countries and the United States, where it generally affects fewer than 1 in 100,000 people.

Riskfactors

Research show that people with Behçet’s disease, especially those of Middle Eastern and Asian descent, have an increased frequency of certain “human leukocyte antigens” (HLAs), specifically HLA-B51, than the general population, which may increase the risk (predispose) to have the disease.

Cause

The cause of Behçet disease is unknown. The condition probably results from a combination of genetic and environmental factors, most of which have not been identified. However, a particular variation in the HLA-B gene has been associated with the risk of developing Behçet disease.

The HLA-B gene provides instructions for making a protein that plays an important role in the immune system. The HLA-B gene is part of a family of genes called the human leukocyte antigen (HLA) complex. The HLA complex helps the immune system distinguish the body's own proteins from proteins made by foreign invaders (such as viruses and bacteria). The HLA-B gene has many different normal variations, allowing each person's immune system to react to a wide range of foreign proteins. A variation of the HLA-B gene called HLA-B51 increases the risk of developing Behçet disease by about a factor of six, although the mechanism is not well understood. One-third to two-thirds of people with Behçet disease have the HLA-B51 variation, but most people with this version of the HLA-B gene never develop the disorder.

Other genetic and environmental factors likely contribute to the risk of Behçet disease. Researchers are studying several genes related to immune system function. It also appears likely that environmental factors, such as certain bacterial or viral infections, play a role in triggering the disease in people who are at risk. However, the influence of genetic and environmental factors on the development of this complex disorder remains unclear.

Inheritance

Most cases of Behçet disease are sporadic, which means they occur in people with no history of the disorder in their family. A small percentage of all cases have been reported to run in families; however, the condition does not have a clear pattern of inheritance.

Symptoms

The signs and symptoms of Behçet disease include recurrent ulcers in the mouth and on the genitals, and eye inflammation (uveitis).

Behçet disease is a multi-system disease and it may involve all organs of the body. 

Signs and symptoms may include: Sores inside the mouth or genitals: The earliest symptom of Behçet disease is usually painful canker round or oval sores with reddish borders on the mucous membranes that line the mouth (aphthous stomatitis) or in the skin of the genitalia. They may be shallow or deep and may be single or multiple lesions that typically heal within a few days, up to a week or more, without scarring, but frequently recur.

Eye problems: Symptoms may include inflammation of the back of the eye (posterior uveitis); inflammation of the anterior chamber (anterior uveitis or iridocyclitis); inflammation of the iris accompanied by pain, tearing (lacrimation); and accumulation of pus (hypopyon iritis). The retina may become inflamed resulting in blurred vision, abnormal sensitivity to light (photophobia), and/or inflammation of the thin membranous layer of blood vessels behind the retina (chorioretinitis). Repeated recurrences may result in the partial loss of vision (decreased visual acuity) or complete blindness if the disease is uncontrolled. In some cases, eye abnormalities may be the first symptom of Behçet disease or they may not develop until several years after the sores of the mouth.

Pus-filled lesions and other problems on the skin: Some affected individuals, especially females, may develop lesions that resemble those of erythema nodosum, a skin disorder characterized by the formation of tender, reddish, inflammatory nodules on the front of the legs. These nodules disappear on their own (spontaneously) sometimes leaving faint scars or discoloration (pigmentation). Some people with Behçet disease may develop small eruptions that resemble acne (acneiform eruptions) and/or inflammation that mistakenly appear to affect the hair follicles on the skin (pseudofolliculitis).

Pain in the joints (50% of cases): Affected individuals have pain (arthralgia) and swelling in various joints (knees, wrists, elbows and ankles), before, during, or after the onset of the other symptoms.

Recurring ulcers in the digestive tract: Symptoms vary from mild abdominal discomfort to severe inflammation of the large intestine and rectum accompanied by diarrhea or bleeding.

Problems of the central nervous system (10%-20% of the cases): These symptoms usually appear months or years after the initial symptoms of Behçet disease. Recurring attacks of inflammation involving the brain (parenchymal Neuro-Behçet) or the membranes that surround the brain or spinal cord (meningitis) can result in neurological damage. Symptoms may include headache, cranial nerve palsies, the inability to coordinate voluntary movement (cerebellar ataxia), impaired muscle movements of the face and throat, stroke, memory loss and/or, rarely, seizures.

Inflammation of the blood vessels (vasculitis): Involvement of small vessels is thought to drive many of the problems that the disorder causes. In some instances inflammation of the large veins, particularly those in the legs may occur along with the formation of blood clots (thrombophlebitis). The walls of an involved artery may bulge forming a sac (aneurysm). In very rare cases, blood clots from the veins travel to the lungs (pulmonary emboli) resulting in episodes of chest pain, coughing, difficult or labored breathing (dyspnea), and coughing up blood (hemoptysis).

Diagnosis

Behçet’s disease is hard to diagnose because:

• The symptoms do not usually appear all at once.
• There are other illnesses that have similar symptoms.
• There is no single test to diagnose Behçet’s disease.

Symptoms used to determine if you have the disease include:

• Mouth sores at least three times in 12 months.
• Two of the following:
• Genital sores that go away and come back.
• Swelling of parts of the eye (with vision loss).
• Skin sores.
• Small red bumps that appear after your doctor pricks your skin with a needle.

Because it may take months or even years for all symptoms to appear, it may take a long time before you will know if you have Behçet’s disease. You can help your doctor diagnose the disease by keeping a record of your symptoms and when they occur.

Treatment

Although there is no cure for Behçet disease, people can usually control symptoms with proper medication, rest, exercise, and a healthy lifestyle. The goal of treatment is to reduce discomfort and prevent serious complications such as disability from arthritis or blindness.

Topical medicine is applied directly on the sores to relieve pain and discomfort. For example, doctors prescribe rinses, gels, or ointments. Creams are used to treat skin and genital sores. The medicine usually contains corticosteroids (which reduce inflammation), other anti-inflammatory drugs, or an anesthetic, which relieves pain. Doctors also prescribe medicines taken by mouth to reduce inflammation throughout the body, suppress the overactive immune system, and relieve symptoms. Doctors may prescribe one or more of the medicines listed below to treat the various symptoms of Behçet disease.

• Corticosteroids
• Immunosuppressive drugs (Azathioprine, Chlorambucil or Cyclophosphamide, Cyclosporine, Colchicine, or a combination of these treatments)
• Methotrexate.
• Interferon-alfa, azathioprine, and TNF-α blockers may be tried in rare cases of patients with resistant, prolonged, and disabling attacks.

For ocular disease, azathioprine is the first medication that should be used. For severe eye disease (such as drop in visual acuity, retinal vasculitis, or macular involvement), either cyclosporine A or infliximab may be used in combination with azathioprine and corticosteroids. Interferon-alfa, alone or in combination with corticosteroids, appears to be a second choice in this eye disease.

Prognosis

Most people with Behçet disease can lead productive lives and control symptoms with proper medicine, rest, and exercise. Doctors can use many medicines to relieve pain, treat symptoms, and prevent complications. When treatment is effective, flares usually become less frequent. Many patients eventually enter a period of remission (a disappearance of symptoms). In some people, treatment does not relieve symptoms, and gradually more serious symptoms such as eye disease may occur. Serious symptoms may appear months or years after the first signs of Behçet disease.

NIH genetic and rare disease info

• NIH info on Behçet disease

Behçet disease is a rare disease.

Behçet disease Resources
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