Behcet Disease
Incidence
Most cases occur sporadically, without family history of the disease, but families with several affected members have also been observed. This disease is most common among people of Middle Eastern or Far Eastern descent but is still considered to be a rare disease in these populations. Behcet\\\'s disease occurs in 3 in 100,000 or even 100 in 100,000 people of Chinese and Turkish descent, respectively. Men and women have different propensities for developing this disease but this varies with ethnicity. For example, Behcet\\\'s is more common among Middle Eastern men as well as Japanese and Korean women. Behcet\\\'s Disease typically affects young adults, between the ages of 20-40.
Clinical Characteristics
Behcet\\\'s Disease is a chronic, relapsing inflammatory disease of the blood vessels that can affect several systems including the neurological and vascular systems as well as the mouth, eyes, skin, joints and genitals. Behcet\\\'s Disease is considered an autoimmune disease and as such the exact underlying cause is unknown. The most common clinical feature of this disease is the presence of multiple, recurring ulcers (aphthae) in the mouth. These ulcers can be very small or as large as 2 cm in diameter. The individual ulcers usually disappear within a couple of weeks but some patients have oral ulcers continuously. Genital ulcers appear in 75 percent of individuals with Behcet\\\'s, usually on the scrotum in males and the vulva in females. Fortunately, these genital lesions have a lower risk of recurrence than the oral ulcers but they are more likely to form scars. The genital lesions can also occur internally and cause painful inflammation of the epididymis in males or the fallopian tubes in females. Ulceration of the skin can also occur and does so in about 75 percent of affected individuals. These ulcers can resemble acne, small bruises, nodules or even appear like a rash. The eyes are affected between 25 to 75 percent of the time, depending on the patient\\\'s ethnicity. Typically, North Americans are not as likely to have eye involvement. The symptom of Behcet\\\'s that may be experienced in the eye is a condition called uveitis or inflammation of the iris, ciliary body and choroids. If present, the patient will usually have the condition in both eyes and it is usually recurrent like the rest of the symptoms mentioned thus far. Unfortunately, many cases of uveitis progress to blindness despite treatment. Other changes that can occur in the eye include the development of cataracts, glaucoma and more rarely, ulcers of the eye surface. Less than 20 percent of patients develop neurological disease which may include meningitis, encephalitis, or local paralysis and/or uncoordinated movements. All of these are caused by inflammation in certain areas of the brain and can be life-threatening. The large arteries and veins are affected in about one third of patients and can lead to very serious complications such as heart attacks, blood clots and aneurysms. Arthritis occurs in about half of the patients with this disease and develops after an illness. The most commonly affected joints are the knees, wrists and ankles. Other less frequent but possible symptoms of this disease includes problems in the kidneys, heart, lungs and ulceration of the GI tract. It is believed that the clinical manifestations of Behcet\\\'s Disease are the result of over activity of the immune system triggered by some agent, possibly infectious such as bacteria or viruses. The immune system has difficulty distinguishing innate body components from invading substances, leading to inflammation of specific organs.
Precipitants
There are no precipitants apparently. Each flare up of the disease is unpredictable with respect to the types and severity of the symptoms.
Provocation Tests
No
Diagnostic Procedures
There is no test available that can diagnose this condition and as a result, the diagnosis is made clinically. The most recent diagnostic criteria were established in 1990 and include oral ulcerations with a negative herpes test that occur at least three times in a given year as well as two of the following in the absence of other systemic diseases: 1) recurrent genital ulcers. 2) eye involvement as described above. 3) skin findings consistent with Behcet\\\'s Disease. 4) a positive pathergy test (a welt 2mm or more in size that develops 24-48 hours after the oblique insertion of a needle into the skin). This test is similar to an allergy skin test, except that there is no substance in the needle and a positive response means that the patient\\\'s immune system is generally overactive.