Behcet Basics for Primary Care: Diagnosis
Primary care physicians are in a key position to suspect and detect BD in their patients and refer them to a rheumatologist to confirm the diagnosis and initiate a treatment plan.
Behçet disease (BD) is rare in the United States (5.2 per 100,000 population) but may result in significant morbidity and mortality, says the American Behçet's Disease Association (ABDA). Because there is no specific diagnostic test for this multisystem inflammatory disorder and diagnosis is based on clinical criteria, the correct diagnosis often is not made until more than 5 years from the onset of symptoms.
Patient care and treatment often require a multidisciplinary team, and rheumatologists are the main physicians involved. But primary care physicians are in a key position to suspect and detect BD in their patients and refer them to a rheumatologist to confirm the diagnosis and initiate a treatment plan.
The ABDA offers a wealth of practical guidance on the epidemiology, symptoms, and diagnosis of patients with BD. Scroll through the slideshow for highlights.
Where the risk lies. BDis most prevalent in the eastern Mediterranean, Middle East, and eastern Asian rim but may be more common in the United States than previously thought. In fact, prevalence is increasing in all areas of the world.BD occurs mostly in young adults (mean age at onset, 25 to 30 years). Male predominance in eastern countries is declining; females predominate in western countries.BD is associated with the HLA-B51 allele HLA-B*5101 in high prevalence areas.
First sign of trouble. Oral ulceration is the earliest manifestation and most common sign of BD. Ulcers are painful. They range from 1 to 20 mm in size and may be shallow or deep, round or oval, and white or yellow with a red halo. Ulcers may affect the buccal mucosa, tongue, lips, gingiva, tonsils, uvula, palate, or pharynx. Some patients have a single ulcer and others have multiple ulcers, especially during flares. Ulcers heal within 10 to 20 days without scarring.
Genital and other manifestations. Genital ulcers are slightly less common (≈75% of patients with BD).They appear on the scrotum or on the shaft or glans of the penis and may be associated with epididymitis in males; they may affect the vulva, vagina, and cervix in females. The lesions often are larger and deeper than oral ulcers and heal with scarring. Other common manifestations of BD include skin lesions, ocular manifestations, arthritis, GI lesions, and lung and CNS involvement.
Clinical criteria for diagnosis. To aid in classification of patients for diagnosis, International Criteria for Behçet’s Disease (ICBD) guidelines state patients must present with recurrent oral ulcerations (aphthous or herpetiform) at least 3 times in 1 year and with any 2 of recurrent genital ulcerations, eye lesions (uveitis or retinal vasculitis) observed by an ophthalmologist, and skin lesions (eg, erythema nodosum or pseudofolliculitis) found in adults not being treated with corticosteroids.
Pathergy test may help diagnosis. The ICBD guidelines include a positive pathergy test result read by a physician within 24 to 48 hours of testing. In the test, a small, sterile needle is inserted into the skin of the forearm. A small red bump or pustule seen at the site of insertion after 1 or 2 days constitutes a positive result, indicating that the immune system is overreacting to a minor injury. However, only a minority of patients with BD demonstrate the pathergy phenomenon by having a positive test result.
Guideline caveats. The BD criteria are not meant to replace the use of clinical judgment in diagnosis in individual cases. They require the presence of oral ulcerations, which may be absent in ≈3% of patients. Substitution of large vessel disease or acute CNS infarction for missing criteria is acceptable for patients in western countries. Manifestations may not occur simultaneously; they could be separated by several years. Manifestations must be documented or witnessed by a physician for a definitive diagnosis.
Monitoring disease activity. A physician may recognize and monitor mucocutaneous disease activity by recording the number, size, and location of lesions and percentage of time lesions have been present since the patient’s last visit. Frequent ophthalmologic exams are necessary for patients with ocular disease. An assessment should include a careful history and examination with attention to vascular and neurologic systems. Standardized tools for recording and scoring disease activity may be used for individual patients.
The long and short of it. BD clinical manifestations result from a vasculitis that can involve arteries of all sizes and the venous system. The small vessels in mucocutaneous sites and in the eyes are more involved than other organ systems. Patients with BD from various ethnic backgrounds and geographic areas have many clinical, epidemiological, and genetic differences.BD morbidity results mostly from ocular involvement.Mortality generally results from large vessel involvement and CNS disease.
