There are no specific tests to confirm a diagnosis of Behcet's Disease. The diagnosis is based on clinical criteria. It may take several months or years for all the common symptoms of the disease to appear, often making it difficult to obtain a definitive diagnosis. The diagnosis is based on the occurrence of signs and symptoms of the disease and on positive clinical criteria referred to as the International Clinical Criteria for Behcet's Disease.
International Clinical Criteria for Behcet's Disease
An international group of physicians has established a set of guidelines to aid in the classification of Behcet's patients. The International Clinical Criteria for Behcet's Disease classification states patients must present with:
Additionally, patients must present any two of the following:
Doctors attempting to make a diagnosis of Behcet's Disease may order a pathergy test in an attempt to produce a pathergy reaction. The pathergy test is a simple procedure in which a small, sterile needle, is inserted into the skin of the forearm. Occurrence of a small red bump or pustule at the site of needle insertion one to two days following the pathergy test constitutes a positive result. A positive result indicates the immune system is overreacting to a minor injury. Although a positive pathergy test is helpful in the diagnosis of Behcet's Disease, only a minority of Behcet's patients demonstrate the pathergy phenomenon by having a positive test. Patients from the Mediterranean region are more likely to demonstrate a positive response to a pathergy test. However, only 50% of patients in Middle Eastern countries and Japan have a positive reaction. This reaction is far less common in the United States. Additionally, other conditions can occasionally result in positive pathergy tests, therefore, the test is NOT 100% specific.
The pictures below demonstrate the pathergy test:
1) Needle is inserted into skin
2) The area where the needle was inserted is circled
3) Area of the skin is inspected the first day following the pathergy test
4) Area of the skin inspected on the second day following the pathergy test
Prognosis of Behcet's Disease
Most patients diagnosed with Behcet's Disease can lead productive lives. Symptoms can be controlled with proper medication, a healthy diet, rest, and exercise. Many medicines are available to treat symptoms, relieve pain, and prevent complications. When treatment is effective, flares usually become less frequent. Patients may enter a period of remission (a disappearance of symptoms), but symptoms may re-occur and appear months or years following a diagnosis.
Researchers continue to explore possible genetic, bacterial, environmental, and viral causes of Behcet's Disease. Research has lead to new forms of treatment for Behcet's patients. New medications have obtained Orphan Drug Approval and are currently being tested in Clinical Trials.
Credits: NINDS, NIH, ABDA. Pictures courtesy of Johns Hopkins University, Division of Rheumatology. Copyrights reserved.