Behçet disease (BD), also known as Behçet syndrome, is a chronic form of vasculitis (inflammation of the blood vessels) involving four primary symptoms: oral and genital ulcers, ocular inflammation, and arthritis.
Behçet disease was first described in the 1930s by Turkish dermatologist Hulusi Behçet. His observations of the three classic symptoms (oral and genital ulcers and eye inflammation) now define this complex condition. BD also has a unique ability to affect all sizes of blood vessels, including arteries and veins. Symptoms related to vasculitis, such as inflammation of joints, gastrointestinal areas, or the central nervous system , are also common.
Incidence of BD is very rare in the United States with approximately five in 100,000 people developing the syndrome. In Middle Eastern and Asian countries between Iran and Japan (known as the "Old Silk Route"), BD is quite prevalent. Incidence in these countries is double that of the United States.
More than twice as many females are diagnosed with BD than males in the United States. However, in Middle Eastern and Asian areas, significantly more men are affected than females.
Causes and symptoms
Behçet disease is caused by an autoimmune response that triggers inflammation of the blood vessels. Researchers have discovered a gene, HLA-B51, which predisposes an individual to BD. However, not all individuals with this gene develop the disease. The specific event leading to onset of BD is not known, but there are speculations that it may be related to the following:
- herpes simplex virus infections
- frequent infections of Streptococcus bacteria
- environmental factors
The four primary symptoms of BD are recurring complications that rarely present simultaneously. These include:
- Oral ulcers (aphthous ulcers). Usually the first sign of disease, these sores resemble common canker sores, but are present in greater number, larger size, and occur more frequently. They may be painful and persist for up to two weeks.
- Genital ulcers. Similar in appearance to oral ulcers, genital sores typically occur on the scrotum in males and in the vulva in females. These ulcers are painful.
- Ocular inflammation (uveitis). May affect the front of or behind the eye, or both together. Inflammation of the middle eye area leads to blurred vision, light sensitivity, and possibly loss of sight.
- Arthritis. Temporary inflammation of the joints develops intermittently.
A large number of secondary symptoms are also associated with BD. These affect the following areas:
- Skin. Acne-like outbreaks of red skin sores develop on the legs and parts of the upper body.
- Vascular system. Formation of blood clots may lead to aneurysms or inflammation of veins (thrombosis). This is more frequent in men.
- Gastrointestinal system. Less often, patients may develop ulcers along the digestive tract.
- Central nervous system. Inflammation of the blood vessels in the brain can result in a variety of conditions such as headache , confusion, stroke , or seizures.
Behçet disease is diagnosed based on a set of guidelines established by an international group of physicians. A physician observes clinical signs and symptoms during patient examination. The most recent and accepted guidelines for a positive diagnosis include the presence of recurring oral ulcers (three or more times in one year) and at least two of four secondary symptoms, including recurring genital ulcers, uveitis, skin lesions, a positive pathergy test.
A pathergy test is a skin-prick test to see if a red bump will form at the injection site. If there is a reaction, the test is positive. This test may be given to patients suspected of BD, but it is not an indicator for the disease. Only a small percentage of patients diagnosed with BD actually test positive.
Patients diagnosed with Behçet disease require a diverse treatment team due to the variety of symptoms and complications. The primary specialist is usually a physician who specializes in arthritis (rheumatologist). In addition, the team includes a dermatologist (skin), an ophthalmologist (eyes), a gynecologist or urologist (genital), a gastroenterologist (digestive system), and a neurologist (nervous system).
Treatment is focused on the symptoms. Several medications are available to minimize discomfort caused by these symptoms.
Most treatment efforts attempt to reduce pain and inflammation. Corticosteroids such as Prednisone are prescribed since they are effective at regulating inflammatory responses. These may be administered as injections, pills, or creams. Immunosuppresant drugs such as cyclosporine, azathioprine or cyclophosphamide help suppress the immune system's response to a less-active state. Both corticosteroids and immunosuppresants can have serious side effects. Patients must be closely monitored by a physician while using these medications.
The use of interferon alpha 2a and 2b has been an effective treatment for ulcers and arthritis in patients who were less responsive to standard treatment regimens. Thalidomide has also shown potential as a treatment for BD. A complication of thalidomide is neuropathy. Thalidomide should not be used by women since it causes severe birth defects in fetuses.
Recovery and rehabilitation
Unlike most diseases, BD has symptoms that periodically flare up and then disappear for a period of time. As a result, patients may have long intervals with no complications. After treatment for active symptoms, patients usually require rest due to fatigue . Moderate exercise is also recommended to improve circulation and muscle strength.
As of early 2004, the National Eye Institute was sponsoring two studies and recruiting patients with Behçet disease.
"Evaluation and Treatment of Patients with Inflammatory Eye Diseases" (study number 000204) evaluates patients with inflammatory eye diseases and the success of current therapies. "Biological Markers in Retinal Vasculitis" (study number 030068) is attempting to isolate biological markers related to primary retinal vasculitis by evaluating patients with differing initial causes of the disease.
Additional information on either of these studies can be found at the National Eye Institute (NEI), Patient Recruitment and Public Liaison Office, 9000 Rockville Pike, Bethesda, Maryland, 20892, (800) 411-1222, TTY (866) 411-1010.
For most patients, the prognosis of Behçet disease is good. Individuals typically experience periods of active symptoms followed by periods of remission in which there are no symptoms. The length of these intervals varies, with ulcerous outbreaks lasting a few weeks and other symptoms occurring for longer durations. With proper treatments and medication, patients can continue to lead active lifestyles in most cases.
Development of vascular or neurological complications often indicates a poorer prognosis. Blindness due to ocular inflammation is also prevalent in patients with BD.
In cases in which a patient becomes visually impaired, major lifestyle changes take place. The patient will have to learn adaptive behaviors and new forms of communication. Leader dog assistance or additional caregiver support are also considerations.
Lee, Sungnack. Behçet's Disease: A Guide to Its Clinical Understanding. New York: Springer Verlag, 2001.
Zeis, Joanne. Essential Guide to Behçet's Disease. Uxbridge, MA: Central Vision Press, 2003.
Okada, A. A. "Drug Therapy in Behçet's Disease." Ocular Immunology and Inflammation (June 2001): 85–91.
Lee, Sungnack. "Behçet Disease." EMedicine. February 18, 2004 (May 17, 2004). <http://www.emedicine.com/derm/topic49.htm>.
National Arthritis and Musculoskeletal and Skin Diseases Information Clearinghouse. 1AMS Circle, Bethesda, MD 20892. (301) 495-4484 or (877) 226-4267; Fax: (301) 718-6366. [email protected] <http://www.niams.nih.gov>.
Stacey L. Chamberlin