Behcet’s disease is an inflammatory disorder characterized by the presence of oral aphthous ulcers, genital ulcers, uveitis, and skin lesions.
Behзet’s disease is an inflammatory disorder of unknown cause. There is a striking geographical distribution, it being most common in Turkey, Iran and Japan. The prevalence per 100 000 is 10-15 in Japan and 80-300 in Turkey. There is a link to the HLA-B51 allele (a split antigen of B5), with a relative risk of 5-10; this association is not seen in patients in the USA and Europe.
EPIDEMIOLOGY & DEMOGRAPHICS
Behcet’s disease is observed in two different geographic locations.
* One is observed in individuals living in Japan, Korea and Turkey.
a). Prevalence ranges from 1:8000 to 1:11,000;
b). Turley has the highest prevalence at 90 to 390 cases per 110,000;
* The other is observed in individuals living in North America and Northern Europe;
a). Prevalence ranges from 1:25,000 to 1:100,000;
b). Prevalence of Behcet’s disease in the USA is 0.13 to 0.34 cases per 100,000;
* In those areas the prevalence of HLA-B51 is higher in patients with Behcet’s disease.
* Incidence in men and women 1:1.
PHYSICAL FINDINGS & CLINICAL PRESENTATION
* Behcet’s disease typically affects individuals in the third to fourth decade of life and primarily presents with painful aphthous oral ulcers. The ulcers occurs in crops measuring 1 to 10 mm in size and found on the mucous membrane of the cheek, gingiva, tongue, pharynx, and soft palate.
* Genital ulcers are similar to the oral ulcers.
* Decreased vision secondary to either uveitis, keratitis, vitreous hemorrhage, or occlusion of the retinal artery or vein may occur.
* Skin findings including papules, vesicles, folliculitis, and acneiform and erythema nodosum-like lesions can be found on the proximal extremities and trunk.
* Arthritis and arthralgias.
* CNS meningeal findings including headache, fever, and stiff neck can occur. Cerebellar ataxia and pseudobulbar palsy occur with involvement of the brainstem.
* Vasculitis leading to both arterial and venous inflammation or occlusion can result in signs and symptoms of a myocardial infarction, intermittent claudication, deep vein thrombosis, hemoptysis, and aneurysm formation.
The cardinal clinical feature is recurrent oral ulceration. The international criteria for diagnosis require oral ulceration and any two of the following: genital ulcers, defined eye lesions, defined skin lesions, or a positive skin pathergy test. Oral ulcers can be aphthous or herpetiform. The eye lesions include an anterior or posterior uveitis or retinal vascular lesions.
Cutaneous lesions consist of erythema nodosum, pseudofolliculitis and papulopustular lesions. Other manifestations include a self-limiting peripheral mono- or oligoarthritis affecting knees, ankles, wrists and elbows; gastrointestinal symptoms of diarrhoea, abdominal pain and anorexia; pulmonary and renal lesions; a brainstem syndrome, organic confusional states and a meningoencephalitis. All the common manifestations are self-limiting except for the ocular attacks. Repeated attacks of uveitis can cause blindness.
The pathergy reaction is highly specific to Behзet’s disease. Skin injury, by a needle prick for example, leads to papule or pustule formation within 20 - 40 hours. Blood tests usually show raised ESR and CRP but not autoantibodies.
The etiology of Behcet’s disease is unknown. An immune-related vasculitis is thought to lead to many of the manifestations of Behcet’s disease. What triggers the immune response and activation is not yet known.
According to the International Study Group for Behcet’s disease, the diagnosis of Behcet’s disease is established when recurrent oral ulceration is present along with at least two of the following:
* Recurrent genital ulceration;
* Eye lesions;
* Skin lesions;
* Positive pathergy test.
* Ulcerative colitis;
* Crohn’s disease;
* Lichen planus;
* Herpes simplex infection;
* Reiter’s syndrome;
* Ankylosing spondylitis;
* Hypereosinophilic syndrome;
* Sweet’s syndrome.
The diagnosis of Behcet’s disease is a clinical diagnosis. Laboratory tests and x-ray imaging may be helpful in working up the complications of Behcet’s disease or excluding other diseases in the differential.
There are no diagnostic laboratory tests for Behcet’s disease.
CT scan, MRI, and angiography are useful for detecting CNS and vascular lesions.
Treatment is directed at the patient’s clinical presentation (for example: mucocutaneous lesions, ocular lesions, arthritis, GI, CNS, or vascular lesions).
Corticosteroids, immunosuppressive agents and ciclosporin are used for chronic uveitis and the rare neurological complications. Colchicine helps erythema nodosum and joint pain. Thalidomide may be useful in some cases although side-effects of drowsiness and peripheral neuropathy are common. It should not be used in pregnant women because of phocomelia (limb abnormalities).
ACUTE GENERAL Rx
* Oral and genital ulcers are treated with:
a). Topical corticosteroids (for example: triamcinolone acetonide ointment applied tid);
b). Tetracycline tablets 250 mg dissolved in 5 cc water and applied to the ulcer for 3 min;
c). Colchicine 0.5 to 1.5 mg / kg / day PO;
d). Thalidomide 100 to 300 mg PO daily;
e). Dapsone 100 mg PO daily;
f). Pentoxifyline 300 mg / day PO;
* Ocular lesions
a). Anterior uveitis is treated by an ophthalmologist with topical corticosteroids (for example: betamethasone drops 1 to 2 drops tid). Topical injection with dexamethasone 1 to 2 mg has also been tried;
* CNS disease;
a). Chlorambucil 0.1 mg / kg / day is used in the treatment of posterior uveitis, retinal vasculitis, or CNS disease. Patients not responding to chlorambucil can be tried on cyclosporine 5 to 6.5 mg / kg / day;
b). In CNS vasculitis, cyclophosphamide 2 to 3.5 mg / kg / day is used. Prednisone can be used as an alternative.
a). NSAIDs (for example: ibuprofen 400 to 800 mg tid PO or indomethacin 50 to 75 mg / day PO);
b). Sulfasalzine 1 to 3 g / day PO is an alternative treatment;
* GI lesions
a). Sulfasalizine 1 to 3 g / day PO;
b). Prednisone 40 to 60 mg / day PO;
* Vascular lesions
a). Prednisone 40 to 60 mg / day PO;
b). Cytotoxic agents as mentioned above;
c). Heparin 5000 to 20,000 U / day followed by oral warfarin.
* Chronic therapy is usually continued for approximately 1 year after remission.
* Surgery may be indicated in patients with complications of bowel perforation, vascular occlusive disease, and aneurysm formation.
* The aphthous oral ulcers last 1 to 2 week recurring more frequently than genital ulcers;
* Approximately 30% of patients with ocular lesions become blind;
* The disease course is unpredictable;
* Complications include:
b). Cerebrovascular accident (stroke);
c). Aneurysm rupture;
d). Peripheral lower-extremity ischemia;
e). Mesenteric ischemia;
f). Myocardial infarction.