Adamantiades Behjet disease (ABD)

Adamantiades Behjet Disease (ABD)1-Is a chronic , relapsing occlusive vascular is of unknown etiology, 2-Characterized , in part by a uveitis that can affect both the anterior and posterior segment of the eye, often simultaneously.

History1) The symptoms of this disease were described as early as 2500 years ago , but it was in the early 20th century that its clinical features were more completely described by Behjat. Most Common Involved Area in the World1-In the eastern Mediterranean countries and in the eastern rim of Asia particularly along old silk route.

Prevalence 80- 300 cases per 100000 inhabitants in turkey to 80-10 per 100000 in Japan or 0.4 per 100000 in the United States.

Genders The complete type of Behjat is most common in men.Onset The main age of onset is between 25 and 35 years.

Inheritance 1-Most cases are sporadic 2-There have been some familial cases.Diagnosis 1-Is clinical2-4 major criteria are:a . recurrently oral aphthaeb . skin lesions including erithema nodosum and acneiform eruptions.c . recurring genital ulcers d . Intraocular inflammation 1-The presence of all 4 major symptoms is considered the complete form of inflammation 2-The incomplete form has 3 major criteria which can occur at different times

Is a Multi System Disease It can predominantly affect one of these systems like nervous, ocular, intestinal and vascular .

Laboratory tests that can help confirming the diagnosis inclube a 1-Pathergy test (skin prick)2-HLA-B 51 and nonspecific immunologic factors such as ESR and C- reactive protein they can help diagnosis of suspected cases they are not , in and of themselves diagnostic for a ABD.Non Ocular Systemic Manifestation 1) Mucosal ulcers in lips, gums, palate, tongue, uvula and posterior pharynx which last for 7- 10 days. Skin lesions Can include painful or recurrent lesions of erythematic nodsum often over extensor surfaces such as the tibia but also the face, neck and buttocks. Nearly 40% of patients exhibit cutaneous pathergy, which is characterized by the development of a sterile pustule at the site of a vein punctuate or an injection, but is not pathognomic of ABD.

Genital ulcers appear grossly similar to oral aphthous ulcers. In male patients, they can occur on the scrotum or penis. In female can appears on the vulva and vaginal mucosa Systemic vasculitis may occur and any size artery or vein in the body may be affected (25% of cases) that lead to, arterial occlusion, aneurysm, venous occlusion and varices.

50% of these patients develop arthritis, knee joint is most affected.

Ocular Manifestations Severe vision loss can occur in up to 25% of ABD patients. More severe in men, and more men are affected, 80% of cases can be bilateral .

Uuveitis Is a non granulomatous necrotizing obliterative vacuities that can affect any or all portions of the uveal tract. Anterior uveitis may be the only manifestation with hypopyon in 25% of cases. It can resolve spontaneously, have relapses, posterior synechiae & PAS .

Essential Retinal Findings are1- Obliterative, necrotizing retinal vasculitis, that affects both the arteries and the veins in the fundus and includes a) BRVOb) BRAOc) vascular sheathing d) CMERetinal ischemia can lead to retinal neovascularization and even neovasculariztion of iris and neovascular glaucoma. Sclerotic vesselsRepeated retinal vaculitis and occlusion lead to white and sclerotic vessel .Differential diagnosisThe ischemic nature of the vacuities and retinitis may be confused with ARN syndrome.Optic atrophyThe optic nerve is affected in 25% of ABD patients and lead to progressive optic atrophy as a result of the vaculitis affecting the arterioles that supply blood to the optic nerve.

Pathogenesis ABD may be considered an autoimmune disease.male > female Fluorescein angiography demonstrates marked dilation and occlusion of retinal capillaries with perivascular staining, retinal ischemia, leakage of fluorescein into the macula. Differential Diagnosis 1-Reiter syndrome2-Sarcoidosis 3-Systemic vasculitis like SLE PAN, Wegner granulomatosis4-Viral retinitis

Treatment The most commonly used agents include: 1-Corticosteroids 2-Cytotoxic drugs 3-Colchicine 4-Cyclosporine 5-Tacrolimus

Corticosteroids

1-Used for acute attack and controlling the disease 2-Most patients will eventually become resistant to steroids. Dose 1.5 mg/kg/day of prednisolone with gradual taper, is extremely useful in contorting acute inflammation. 2- Immunomodulatory Medications a) Azathioprine is useful in preserving visual acuity and for oral and genital ulcers and arthritis. b) Chlorambucil has been found to be effectives and safe in treatment of ABD even at relatively low doses. It is the most effective of immunomodulatory agents.

CyclophosphamideCycloposphamide used with some success and less effective than chlorambucil Both chlorambucil and cyclophosphamide are more effective than cylosporine A. Side effects are Leukopenia Cyclosporine A at 5 mg/kg/day Inflixmab appears promising for the treatment of ABD.Prognosis Severe vision loss can occur in up to 25% of ABO patients, but in the past 15 years earlier initiation of immunomodulatory therapy resulted in better visual outcomes.