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Behçet’s Syndrome


Last updated: 05/17/2023
Years published: 1986, 1987, 1988, 1989, 1990, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2002, 2004, 2009, 2012, 2015, 2018, 2023


NORD gratefully acknowledges Ronald R. Butendieck, MD, FACP, Division of Rheumatology, Department of Internal Medicine, Mayo Clinic, Jacksonville, Florida, for assistance in the preparation of this report.

Disease Overview

Behçet’s syndrome is a rare multisystem inflammatory disorder characterized by ulcers affecting the mouth and genitals, various skin lesions and abnormalities affecting the eyes. Symptoms include mucous membrane lesions of the mouth (canker sores) and genitals (ulcers) that tend to disappear and recur spontaneously. Inflammation of the eyes (anterior uveitis, posterior uveitis, or panuveitis) also affects individuals with Behçet’s syndrome. Additional systems of the body may also be affected including the joints, blood vessels, central nervous system and/or digestive tract. The exact cause of Behçet’s syndrome is unknown.

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  • Adamantiades-Behcet's syndrome
  • BD
  • Behcet's disease
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  • neuro-Behcet
  • ocular-Behcet
  • vasculo-Behcet
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Signs & Symptoms

The earliest symptom of Behçet’s syndrome is usually painful canker sores on the mucous membranes that line the mouth (aphthous stomatitis). The sores are usually round or oval with reddish (erythematous) borders that may occur anywhere within the mouth. They may be shallow or deep and may appear as a single lesion or a cluster of multiple lesions. The sores typically heal within a few days, up to a week or more, without scarring, but frequently recur. They may precede other symptoms of Behçet’s syndrome by several years. Sometimes similar sores may appear on the genitals, specifically the scrotum and shaft of the penis in males and the vulva in females. The sores are also round and painful but may be larger and deeper than those affecting the mouth. These sores also recur, but unlike oral lesions, may tend to scar.

Behçet’s syndrome may also affect the eyes. Symptoms may include inflammation of the back of the eye (posterior uveitis) and inflammation of the front of the eye (anterior uveitis or iridocyclitis). Inflammation of the iris accompanied by pain, tearing (lacrimation) and the accumulation of pus (hypopyon iritis) may also occur. 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). Although the lesions that cause inflammation in various parts of the eyes may resolve, 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’s syndrome. In other cases, they may not develop until several years later.

Individuals with Behçet’s syndrome may also exhibit the formation of small, pus-filled growths on the skin (pustules). 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 individuals with Behçet’s syndrome may develop small eruptions that resemble acne (acneiform eruptions) and/or inflammation that mistakenly appear to affect the hair follicles on the skin (pseudofolliculitis).

In approximately 50 percent of cases of Behçet’s syndrome, affected individuals experience pain (arthralgia) and swelling in various joints of the body (polyarthritis). This may occur before, during, or after the onset of the other symptoms associated with Behçet’s syndrome. Pain, which can range from mild to severe, typically affects the joints of the knees, wrists, elbows and ankles, and may become chronic. Lasting damage to affected joints is extremely rare.

Individuals with Behçet’s syndrome may also have 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.

Approximately 10%-20% of individuals with Behçet’s syndrome also have involvement of the central nervous system. These symptoms usually appear months or years after the initial symptoms of Behçet’s syndrome. Recurring attacks of inflammation involving the brain (parenchymal Neuro-Behçet) or the membranes that surround the brain or spinal cord (meningitis or meningoencephalitis) can result in neurological damage. Symptoms may include headache, the inability to coordinate voluntary movement (cerebellar ataxia), impaired muscle movements of the face and throat (pseudobulbar palsies), stroke and/or rarely, seizures.

Behçet’s syndrome causes 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).

Unlike most diseases which are classified as vasculitis, involvement of the kidneys or peripheral nerves is very rare.

It is especially important to identify Behçet’s disease when there is ocular, central nervous system or large blood vessel involvement as manifestations are usually the most serious.

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The exact cause of Behçet’s syndrome is not known. Studies suggest that some people may have a genetic predisposition to the condition. A genetic predisposition means that a person may carry a gene for a disease, but it may not be expressed unless something in the environment triggers the disease. Researchers have demonstrated that certain individuals with Behçet’s syndrome, especially those of Middle Eastern and Asian descent, have an increased frequency of certain human leukocyte antigens (HLAs) in the blood. Individuals with Behçet’s syndrome are more likely to have HLA-B51 than the general population. The possible role of HLA-B51 in predisposing individuals to Behçet’s syndrome and its overall association with the disorder is unknown. Other genetic markers and their role in the development of Behçet’s disease are being studied. Viral or bacterial infections have also been suggested as a possible cause for the disorder. Still another theory is that the disease is an auto-inflammatory disorder in which the body loses the ability to appropriately regulate and control inflammation.

Autoimmune disorders are caused when the body’s natural defenses against “foreign” or invading organisms (e.g., antibodies) begin to attack healthy tissue for unknown reasons. While investigation is ongoing, no autoantibodies to date have been identified to suggest that Behçet’s syndrome is an autoimmune disease.

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Affected populations

Behçet’s syndrome is a rare disorder in the United States and Western Europe. It occurs most frequently in the Middle East and Asia, along ancient trading routes between the Mediterranean basin and eastern Asia, known as the Silk Road. Turkey has the highest prevalence rate (80-370 cases per 100,000); Japan, Korea, China, Iran, and Saudi Arabia also have high prevalence rates. The disorder is the leading cause of blindness in Japan. The age of onset is typically between 30 and 40 years.

In the United States and Australia, this syndrome is more common in women than men, and the symptoms tend to be less severe. Men may be more commonly affected in Middle Eastern countries and usually have more severe disease. Central nervous system involvement is more common among native populations of northern Europe and the United States.

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The diagnosis of Behçet’s syndrome is made based on the clinical judgment of a physician. Criteria have been accepted, based upon the identification of recurrent oral ulcerations (aphthous stomatitis) that occur along with at least two of the following: eye lesions, skin lesions, recurrent genital ulcerations and a positive pathergy test. During a pathergy test, a physician pricks an individual with a sterile needle. A positive outcome occurs if a reddish spot (nodule or pustule) forms 48 hours after the prick. However, these criteria have been formed so that patients might be included in clinical studies (“classification criteria”) and are not really “diagnostic” criteria.

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Standard Therapies

The treatment of Behçet’s syndrome is directed toward the specific symptoms that are apparent in each individual. Specific therapies for Behçet’s syndrome are symptomatic and supportive. Severity of the condition as well as the patient’s age and sex may all affect treatment decisions. Spontaneous remission over time is common for individuals with Behçet’s syndrome.

Oral and genital ulcerations may be treated with topical application of corticosteroid-containing preparations to the affected areas to assist in aborting developing attacks. Mouthwash containing a local anesthetic such as lidocaine or diphenhydramine may temporarily relieve pain. For recurrent attacks, colchicine can be effective in preventing recurring attacks of oral and genital ulcers. Apremilast is now FDA approved for the treatment of recurrent oral ulcerations in patients with Behçet’s. More aggressive therapies such as azathioprine, thalidomide, interferon-alpha and anti-TNF agents may be considered.

Individuals who have arthritis associated with Behçet’s may respond to nonsteroidal anti-inflammatory drugs (NSAIDs) and colchicine. Treatment with azathioprine and anti-TNF agents can be used for more aggressive or refractory disease.

Identification of eye inflammation requires close collaboration with an ophthalmologist as treatment is based on the location of eye inflammation and severity. Treatment may include eye drops containing corticosteroids to relieve pain. For more aggressive or refractory disease, oral corticosteroids combined with an immunosuppressant drug such as azathioprine or anti-TNF are used to control the progression of eye disease.

Sulfasalazine, azathioprine, and corticosteroids may be administered to treat inflammatory bowel disease and gastrointestinal lesions associated with Behçet’s. Central nervous system and vascular abnormalities may be treated with corticosteroids as well, often in conjunction with immunosuppressive agents. In patients with clotting of major blood vessels, systemic anticoagulants and immunosuppressants should be considered.

Inflammation of the joints, skin, and/or mucous membranes or other organs may be reduced with oral corticosteroid drugs. However, corticosteroids do not prevent recurring episodes of symptoms and may not reduce damage when used alone. Therefore, immunosuppressive agents such as azathioprine, methotrexate, cyclosporine or chlorambucil may be employed for improved control of inflammation and organ protection. Experience is evolving with the use of interferon-alpha and with agents which inhibit tumor necrosis factor (TNF) in the treatment of Behçet’s disease.

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Clinical Trials and Studies

There are a variety of therapies that are being investigated for the treatment of Behçet’s. Immunosuppressive drugs such as azathioprine (Imuran), chlorambucil (Leukeran), cyclophosphamide (Cytoxan), cyclosporine (Sandimmune), interferon alpha, anti-TNF inhibitors, tocilizumab (Actemra), ustekinumab (Stelara), secukinumab (Cosentyx) and tofacitinib (Xeljanz) continue to be studied for use as treatments for the disorder. Apremilast is currently the only FDA approved medication for Behçet’s with the indication for treatment of recurrent oral ulcerations in patients with Behçet’s. Investigation for other potential benefits of apremilast including skin, genital ulcers and joints are ongoing.

Information on current clinical trials is posted on the Internet at https://clinicaltrials.gov/ All studies receiving U.S. Government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov

Some current clinical trials also are posted on the following page on the NORD website: https://rarediseases.org/for-patients-and-families/information-resources/info-clinical-trials-and-research-studies/

For information about clinical trials sponsored by private sources, contact: https://www.centerwatch.com/

For information about clinical trials conducted in Europe, contact: https://www.clinicaltrialsregister.eu/

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RareConnect offers a safe patient-hosted online community for patients and caregivers affected by this rare disease.  For more information, visit www.rareconnect.org.

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Hatemi G, Seyahi E, Fresko I, Talarico R, Uçar D, Hamuryudan V. Behçet’s syndrome: one year in review 2022. Clin Exp Rheumatol. 2022 Sep;40(8):1461-1471. doi: 10.55563/clinexprheumatol/h4dkrs. Epub 2022 Jul 26. PMID: 35894066.

Takeno M. The association of Behçet’s syndrome with HLA-B51 as understood in 2021. Curr Opin Rheumatol. 2022 Jan 1;34(1):4-9. doi: 10.1097/BOR.0000000000000846. PMID: 34690278; PMCID: PMC8635258.

Toledo-Samaniego N, Oblitas CM, Peñaloza-Martínez E, Del-Toro-Cervera J, Alvarez-Sala-Walther LA, Demelo-Rodríguez P, Galeano-Valle F. Arterial and venous involvement in Behçet’s syndrome: a narrative review. J Thromb Thrombolysis. 2022 Jul;54(1):162-171. doi: 10.1007/s11239-022-02637-1. Epub 2022 Feb 19. PMID: 35182310.

van der Houwen TB, van Hagen PM, van Laar JAM. Immunopathogenesis of Behçet’s disease and treatment modalities. Semin Arthritis Rheum. 2022 Feb;52:151956. doi: 10.1016/j.semarthrit.2022.151956. Epub 2022 Jan 10. PMID: 35038644.

Capittini C, Rebuffi C, Lenti MV, Di Sabatino A, Tinelli C, Martinetti M, De Silvestri A. Global Meta-Analysis on the Association between Behcet Syndrome and Polymorphisms from the HLA Class I (A, B, and C) and Class II (DRB1, DQB1, and DPB1) Genes. Dis Markers. 2021 Dec 13;2021:9348697. doi: 10.1155/2021/9348697. PMID: 34938376; PMCID: PMC8687777.

Mattioli I, Bettiol A, Saruhan-Direskeneli G, Direskeneli H, Emmi G. Pathogenesis of Behçet’s Syndrome: Genetic, Environmental and Immunological Factors. Front Med (Lausanne). 2021 Oct 8;8:713052. doi: 10.3389/fmed.2021.713052. PMID: 34692721; PMCID: PMC8531401.

Nguyen A, Upadhyay S, Javaid MA, Qureshi AM, Haseeb S, Javed N, Cormier C, Farooq A, Sheikh AB. Behcet’s Disease: An In-Depth Review about Pathogenesis, Gastrointestinal Manifestations, and Management. Inflamm Intest Dis. 2021 Nov 4;6(4):175-185. doi: 10.1159/000520696. PMID: 35083283; PMCID: PMC8740277.

Turk MA, Hayworth JL, Nevskaya T, Pope JE. Ocular manifestations of Behçet’s disease in children and adults: a systematic review and meta-analysis. Clin Exp Rheumatol. 2021 Sep-Oct;39 Suppl 132(5):94-101. doi: 10.55563/clinexprheumatol/pt60bc. Epub 2021 Sep 17. PMID: 34596037.

Yazici Y, Hatemi G, Bodaghi B, Cheon JH, Suzuki N, Ambrose N, Yazici H. Behçet syndrome. Nat Rev Dis Primers. 2021 Sep 16;7(1):67. doi: 10.1038/s41572-021-00301-1. PMID: 34531393.

Zając H, Turno-Kręcicka A. Ocular Manifestations of Behçet’s Disease: An Update on Diagnostic Challenges and Disease Management. J Clin Med. 2021 Nov 5;10(21):5174. doi: 10.3390/jcm10215174. PMID: 34768694; PMCID: PMC8584626.

NINDS Behçet’s Disease Information Page. Date last modified:Jan 20, 2023. https://www.ninds.nih.gov/Disorders/All-Disorders/Behcets-Disease-Information-Page. Date last modified: May 23, 2017. Accessed April 17, 2023

Davey-Ranasinghe N. Behçet Disease. Updated: Oct 19, 2022. Emedicine. https://emedicine.medscape.com/article/329099-overview. Accessed April 17, 2023.

Online Mendelian Inheritance in Man (OMIM). The Johns Hopkins University. Behçet Syndrome. Entry No: 109650. Last Edited 03/24/2022. Available at: https://omim.org/entry/109650.  Accessed April 17, 2023.

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