What Is Behçet’s Syndrome?

  • Ezgi Uslu Icli Medical Doctor - Gazi University Medical School, Turkey

Have you ever heard about a condition called Behçet’s Syndrome or Behçet’s Disease? Although it is rare, Behçet’s syndrome is a complex condition affecting various parts of the body and can be difficult to diagnose. 

Behçet’s syndrome is a long-term condition which is characterized by inflammation of the blood vessels and various tissues in the body. The reason behind Behçet’s syndrome is not yet fully understood.

Behçet’s syndrome might potentially cause a wide range of problems, some of which can be serious or even life-threatening. If you want to learn more about this complex and potentially dangerous condition, you can increase your knowledge by reading our article, where you can find the important aspects of Behçet’s syndrome.


Behçet’s Syndrome, also known as Silk Road Disease, is a chronic inflammatory vasculitis, which means a long-term inflammation of the blood vessels around the body. Although it mainly involves the eyes or skin, it can involve different parts of the body.

The condition is named after the Turkish professor Hulusi Behçet, who first described the classic symptoms of the condition in 1937, namely mouth and genital ulcers along with eye involvement.1

There is an ongoing debate about whether the condition should be called Behçet’s disease or Behçet’s syndrome. Because the condition is poorly understood and may present with various symptoms, some physicians prefer the broader term syndrome instead of disease, which might be suggestive of a single entity.

Despite occurring worldwide, Behçet’s syndrome is mostly seen along the “Silk Road” with the highest cases found in Turkey, Japan, and Iran. Although it is less common in the Western world, the prevalence has gradually increased due to immigration.2,3

People who are affected by Behçet’s syndrome are mostly between 20-40 years old, although it can also affect children and elderly people.2

Gender distribution is variable around the world; however, assigned males at birth are more likely to present with severe symptoms.2 


The exact cause of Behçet’s syndrome is still unknown. However, the role of genes, environmental factors, and the immune system have been indicated. 

Genetic markers HLA-B5 and HLA-B51 are present in some patients with Behçet’s syndrome. According to a group of scientists, the condition can be triggered by infections in some people with said genetic markers.

It has been shown that the condition has an autoimmune nature. The indicators are: the inflammatory response, reactivation and remission course, and success with immunosuppressive medications.2

Signs and symptoms

Behçet’s syndrome can affect different parts of the body and cause various signs and symptoms. At times, signs and symptoms might get better, which is known as the remission period. However, they might sometimes get worse during relapses or flare-ups.

Oral and genital ulcers

Painful oral ulcers can be found in almost all cases of Behçet’s syndrome and they might be similar to normal mouth ulcers in appearance. Oral ulcers happen repeatedly and they are the first sign of the condition in up to 80% of the patients.

Genital ulcers are also a classic feature of Behçet’s syndrome. They look similar to oral ulcers; however, they are more likely to form scar tissue and happen less frequently. They are mostly found in the scrotum in assigned males at birth and in the labia majora in assigned females at birth.4

Skin lesions

Skin lesions seen in Behçet’s Syndrome are not specific to the condition itself. That means they can also be seen in other conditions. However, they are essential for diagnosis.

Some of the skin lesions seen in Behçet’s syndrome include erythema nodosum, thrombophlebitis, papulopustular lesions (raised red rash with pus-filled blisters),  and skin ulcers.4

Eye inflammation and vision problems

Eye involvement is seen in 30 to 70% of patients and usually occurs after oral or genital ulcers. However, it might still be the first feature in 10 to 20% of the cases. 

Behçet’s syndrome can affect the parts of the eye called retina and uvea and might result in vision problems in some patients. Uveitis is the typical eye inflammation seen in Behçet’s syndrome, which usually happens in flare-ups affecting both eyes.4 

Joint pain and swelling

45 to 60% of Behçet’s syndrome patients might experience joint symptoms, which include joint pain, swelling, and joint inflammation. The most affected joints are the knees, ankles, hips, elbows, and wrists.4

Blood vessel involvement

Behçet’s syndrome might affect all types and sizes of blood vessels. Blood vessel involvement is an important cause of complications and death in Behçet’s syndrome. Inflammation inside the vessels might cause clot formation and bulging of vessel walls, known as aneurysms.2 

The most common vessel involvements are deep vein thrombosis of the limbs and repeated superficial venous thrombosis. Clot formation in larger vessels is seen less commonly.4 

Central nervous system issues

Central nervous system involvement, also known as Neuro-Behçet’s disease, is seen in up to 10% of the patients and the outcomes are not favourable. It might affect different parts of the nervous system and the symptoms depend on the affected part.2,4

Possible symptoms include headache, double vision, loss of balance, fits, paralysis on one side of the body, and personality changes. 

Digestive system involvement

Inflammation and ulcer formation throughout the digestive tract might cause symptoms such as diarrhoea, bleeding, tummy pain, and fever.2 

Other symptoms

Fatigue can be seen as a result of inflammation and it might be associated with depression and anxiety. Kidney, heart, and lung involvement can be uncommon to present.2,4

Getting diagnosed

Due to variable presentations, diagnosis is a challenge and there are no specific diagnostic tests available to detect Behçet’s syndrome. Diagnosis is made by clinical criteria and excluding other possible diseases.5

The diagnosis is made by the presence of repeated mouth ulcers occurring at least three times a year plus any two of the following:4

  • Repeated genital ulcers
  • Eye involvement
  • Skin lesions
  • Positive pathergy test results with reading performed 24-48 hours after the test

The pathergy test, also known as the skin pathergy reaction (SPR), is a nonspecific response by your immune system, which occurs as a result of tissue damage by pricking a sterile needle. The formation of a red raised rash equal to or larger than 2 mm, or the formation of a pus-filled blister after 24 to 48 hours following the needle pricking, is accepted as a positive result. However, positive results can be found in other diseases as well.5

Excluding other possible diseases is also important to reach a definitive diagnosis. Therefore, your doctor might order investigations such as urine analysis, chest X-ray, coeliac screen, stool sample, autoimmune screen, coagulation screen, and antiphospholipid antibodies, mouth and genital ulcer swab, and eye swab. Further investigations such as biopsies and further scans might also be needed as a next step.2

Managing behçet's syndrome

Because Behçet’s syndrome involves different systems, a multidisciplinary approach is usually needed for better outcomes. Age, gender, severity, type of organ involvement, and patient choices should be considered when deciding treatment options.

The main goal of management is preventing flare-ups and major organ involvement that may result in death. Untreated eye, vessel, nervous system, and digestive system involvement might cause serious problems and even death.6

The main medicines used in the management include the following:

  • Corticosteroids - can be used as eyedrops, creams, mouthwash, gels, or can be taken by mouth depending on the symptom.
  • Immunosuppressants - can be taken by mouth or can be given as injections.
  • Biological therapies - can be given into a vein (intravenously) or by injection under the skin (subcutaneous injection)

Usually, combinations of different medicines are used in the treatment. The duration of which depends on the severity of the symptoms. Some individuals may only need to take medicines during a flare-up; however, some may need to take medicines on a long-term basis to prevent complications.

Blood clots and aneurysms associated with Behçet’s syndrome are usually treated with a combination of corticosteroids and immunosuppressants. On occasions, a surgical procedure might be needed for the treatment of aneurysms. The use of anticoagulants for clot formation in Behçet’s syndrome is controversial due to the underlying inflammation and increased risk of vessel rupturing. 

Behçet’s is a long-term condition. Therefore, emotional and welfare support along with joining support groups might be helpful in the management.

Potential complications

Behçet’s Syndrome may potentially cause certain complications and some of them might result in death. 

Most of the complications occur due to eye and nervous system involvement. 

Most important complications include:7

  • Blindness
  • Rupture of an aneurysm in large arteries of the lung and heart
  • Nervous system involvement might cause stroke and long-term health problems
  • Increased risk of miscarriages due to inflammation of the placenta

Other complications include pericarditis, myocarditis, endocarditis, clot formation and obstruction of vessels, and a bowel perforation.

Early diagnosis and immediate treatment can help improve the outcomes of the treatment and decrease the risk of complications.7  


Behçet’s Syndrome, also known as Silk Road Disease, is a rare chronic (long-term) inflammatory vasculitis that affects blood vessels and tissues across the body. Its cause remains unclear, possibly involving genetic, immune, and environmental factors. Behçet’s syndrome's classic symptoms include oral and genital ulcers, skin lesions, eye inflammation, joint pain, and vascular problems. The condition displays an intermittent nature, with symptoms coming and going over time. Diagnosis relies on clinical criteria and ruling out other conditions. Management requires a multidisciplinary approach, with treatments ranging from corticosteroids to immunosuppressants. Complications, especially related to eye and nervous system involvement, can be severe. Therefore, early diagnosis and treatment are crucial for better outcomes.


  1. Verity DH, Wallace GR, Vaughan RW, Stanford MR. Behçet’s disease: from Hippocrates to the third millennium. Br J Ophthalmol [Internet]. 2003 Sep [cited 2023 Aug 17];87(9):1175–83. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1771837/
  2. Nair JR, Moots RJ. Behcet’s disease. Clin Med (Lond) [Internet]. 2017 Feb [cited 2023 Aug 17];17(1):71–7. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6297594/
  3. Davatchi F. Behcet’s disease. Int J Rheum Dis [Internet]. 2014 May [cited 2023 Aug 17];17(4):355–7. Available from: https://onlinelibrary.wiley.com/doi/10.1111/1756-185X.12378
  4. Scherrer MAR, Rocha VB, Garcia LC. Behçet’s disease: review with emphasis on dermatological aspects. An Bras Dermatol [Internet]. 2017 Aug [cited 2023 Aug 17];92(4):452–64. Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0365-05962017000400452&lng=en&tlng=en
  5. Alibaz-Oner F, Direskeneli H. Update on the diagnosis of behçet’s disease. Diagnostics [Internet]. 2022 Dec 23 [cited 2023 Aug 17];13(1):41. Available from: https://www.mdpi.com/2075-4418/13/1/41
  6. Karadag O, Bolek EC. Management of Behcet’s syndrome. Rheumatology [Internet]. 2020 May 1 [cited 2023 Aug 17];59(Supplement_3):iii108–17. Available from: https://academic.oup.com/rheumatology/article/59/Supplement_3/iii108/5826894
  7. Adil A, Goyal A, Quint JM. Behcet disease. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 [cited 2023 Aug 17]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK470257/
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Ezgi Uslu Icli

Medical Doctor - Gazi University Medical School, Turkey

Ezgi has completed her studies in Medicine in 2017. After graduation, she worked as an emergency doctor followed by work experience as a research assistant in public health as well as undersea and hyperbaric medicine. She worked actively in the frontline during the COVID-19 pandemic as well.
She is passionate about medical writing as it helps increase health literacy and awareness of the public.
She moved to the UK in 2022 and she works as a volunteer in one of the NPOs for children in need.

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