The synonym “Silk Road Disease” for Behcet’s Disease originated from this disease’s prevalence along the region referred to as the “Old Silk Road”. This refers to a trade route from East Asia such as Japan and China to the Mediterranean, spanning countries such as Turkey and the Middle East.

Behçet’s disease is a rare disorder occurring more frequently in the Middle East and Asia, along the Silk Road. Turkey has the highest prevalence rate (80 to 370 cases per 100,000). Japan, Korea, China, Iran, and Saudi Arabia also have high prevalence rates. In the United States and Australia, the syndrome is more common in women than men, and the symptoms tend to be less severe. Men may be more affected in Middle Eastern countries, and usually have more severe symptoms. Involvement of the central nervous system is more common among native populations of northern Europe and the United States. In northern European countries and the United States, this disease generally affects fewer than 1 in 100,000 people.

The direct cause of Behcet’s Disease is still unknown, but it is believed that there are a number of factors including genetic, immune, and environmental that combine to cause the inflammation and resulting skin sores. 

• Genetic factors: There is no known gene that is responsible for Behcet’s Disease. However, there is a gene that produces a particular protein known as an antigen that is found in inflammatory tissues of people with Behcet’s Disease. This gene, known as HLA-B51, encodes the antigen B51, which can be found in inflamed tissues such as the eyes and skin. This antigen B51 can sometimes be used as a genetic marker of Behcet’s Disease, meaning that testing for high levels of it in the blood can indicate a diagnosis. However, it is unknown whether this gene and antigen cause the disease in any way or if they are just part of the inflammatory response.. A variation called HLA-B51 increases the risk of developing Behçet’s disease. Although many people with Behçet’s disease have the HLA-B51 variation, most people with this version of the HLA-B gene never develop the disorder. It is unknown how HLA-B51 increases the risk of developing this disease. 

• Autoinflammatory factors: Due to the symptoms of inflammation experienced by those with Behcet’s Disease, one of the causes could be autoinflammation. An autoinflammatory condition occurs when the body triggers inflammation when there is no challenge to the immune system, or when a bacterial or viral infection causes an immune response to target a certain part of the body. This is a defect that causes the body to activate an immune response without a way of shutting it down. 

• Environmental: Environmental factors, such as food, drugs, or exposure to toxins, can impact the way genes are expressed in the body. A person’s DNA cannot be changed by such factors, but the way they are read and translated into proteins that have important functions in the body can change. If DNA is the instructions, gene expression carried out by transcription factors is the ability to interpret instructions. External factors can turn these transcription factors on or off, and change sites on the DNA that these transcription factors recognize to start reading certain genes.

The first signs of Behçet’s disease include painful mouth sores called aphthous ulcers. These occur on the lips, on the tongue, and inside the cheeks. They look like common canker sores and typically heal within one to two weeks. About 75% of people with Behçet’s disease develop similar ulcers on the genitals.

Behçet’s disease can also cause painful bumps and sores on the skin. Most affected individuals develop pus-filled bumps that resemble acne that can occur anywhere. Some also have red, tender nodules called erythema nodosum. These usually develop on the legs, but also occur on the face, neck, and arms.

In more than half of people with Behçet’s disease, there is an inflammation of the eye called uveitis. This is more common in younger people and men and results in blurry vision and an extreme sensitivity to light (photophobia). If untreated, this symptom can lead to blindness.

Less commonly, Behçet’s disease can affect the joints, gastrointestinal tract, large blood vessels, and the central nervous system (brain and spinal cord). Central nervous system abnormalities are among the most serious complications.

The symptoms usually begin from ages twenty to forty, although it 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 many parts of the body, including the central nervous system. The features of Behçet’s 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.

The diagnosis of Behçet’s syndrome is made based on the clinical judgment of a physician. According to the International Study Group guidelines, for a patient to be diagnosed with Behçet's disease, he/she must have oral ulcers (any shape, size, or number at least 3 times in any 12 months period) along with 2 out of the 4 following symptoms: genital ulcers, skin lesions, eye inflammation, pathergy reaction. However, there are cases where not all the criteria can be met and therefore a diagnosis cannot readily be made.

While there is no definitive test to diagnose Behcet’s Disease, several tests can be employed to evaluate the inflammation to blood vessels and the impacts to the brain and spinal cord:

• Blood test

• Urine test

• Scans: x-ray, CT, MRI

• Skin biopsy: removal of a small amount of tissue to evaluate the health of the cells

• Pathergy test: skin prick with a needle to evaluate development of a sore; individuals with Behcet’s Disease often have hypersensitive skin

There is no cure for Behçet's disease, but 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. The type of medicine and length of treatment depend on the person’s symptoms and their severity. A combination of treatments will likely be needed to relieve specific symptoms. Doctors may prescribe rinses, gels, or ointments. The medicine usually contains corticosteroids (which reduce inflammation), other anti-inflammatory drugs, or an anesthetic. Other drugs that may be prescribed in severe cases include immunosuppressive drugs (Azathioprine, Chlorambucil or Cyclophosphamide, Cyclosporine, Colchicine, or a combination of these treatments) and Methotrexate.

In the absence of treatment, there is potential for a severe prognosis causing blindness. There is also the risk of lethal arterial rupture and neurological symptoms potentially causing brain related disorders that may lead to a loss of autonomy. Intensive ophthalmological (eye) care coupled with immunosuppressive treatment has been shown to reduce morbidity greatly.

There are 3 sites of NHS Excellence devoted to the study and diagnosis of Behcet’s Disease. They are all located in England: London, Birmingham, and Liverpool. More information can be found on their website: https://www.behcets.nhs.uk/ 

Exercise can improve the conditions of joints. Exercise such as yoga or Pilates may also help to reduce stress, which can sometimes trigger a flare-up of symptoms. A balanced diet is beneficial to general health.

Behçet’s disease is not contagious. However, long-term conditions can affect the mood, emotions, and confidence of the individual. It can also have an impact on work, social life, and relationships. Talking with a friend, relative, or doctor could help. In addition, contacting support groups is a good way to meet others with Behçet’s disease.

GHR: http://ghr.nlm.nih.gov/condition/behcet-disease

Orphanet: http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=117

ORDR: https://rarediseases.info.nih.gov/gard/848/behcets-disease/resources/1

NORD: http://rarediseases.org/rare-diseases/behcets-syndrome/

OMIM: http://www.omim.org/entry/109650?search=Beh%C3%A7et%E2%80%99s%20Disease&highlight=s%20behcet%20disease

Wikipedia: https://en.wikipedia.org/wiki/Beh%C3%A7et%27s_disease

Arthritis Research UK: http://www.arthritisresearchuk.org/arthritis-information/conditions/behcets-syndrome/self-help-and-daily-living.aspx