[4] Painful genital ulcerations usually develop around the anus, vulva, or scrotum and cause scarring in 75 percent of the patients.

[4] Additionally, patients may present with erythema nodosum, cutaneous pustular vasculitis, and lesions similar to pyoderma gangrenosum.

A rare form of ocular (eye) involvement in this syndrome is retinal vasculitis which presents with painless decrease of vision with the possibility of floaters or visual field defects.

[7][8] Signs and symptoms of acute optic neuropathy include painless loss of vision which may affect either one or both eyes, reduced visual acuity, reduced color vision, relative afferent pupillary defect, central scotoma, swollen optic disc, macular edema, or retrobulbar pain.

When these symptoms occur with concurrent mucocutaneous ulcerations, they raise suspicion of acute optic neuropathy in Behçet's Disease.

[10] Gastrointestinal (GI) manifestations include abdominal pain, nausea, and diarrhea with or without blood, and they often involve the terminal ileum and ileocecal valve.

Serious kidney problems are more common in men typically with a history of large vessel involvement in other parts of the body.

Lesions tend to occur in the brainstem, the basal ganglia and deep hemispheric white matter and may resemble those of multiple sclerosis (MS).

[11] Although infrequent, myocardial infarction (heart attack) with angiographically identified acute coronary artery thrombosis has been reported, including one case with a pathologically demonstrable lesion due to arteritis found at autopsy.

[citation needed] Research suggests that previous infections may provoke the autoimmune responses present in Behçet's disease.

Heat shock proteins (HSPs) are present in some bacteria and serve as a "danger signal" to the immune system.

[17] An association with the GIMAP ("GTPase of the immunity-associated protein") family of genes on the long arm of chromosome 7 (7q36.1) has been reported.

[18] Behçet's disease is considered more prevalent in the areas surrounding the old silk trading routes in the Middle East and in Central Asia.

[20] HLA-B51 is more frequently found from the Middle East to South Eastern Siberia, but the incidence of B51 in some studies was 3 fold higher than the normal population.

[22] At the current time, a similar infectious origin has not yet been confirmed that leads to Behçet's disease, but certain strains of S. sanguinis has been found to have a homologous antigenicity.

[8] CNS involvement in Behçet's disease may lead to intracranial hypertension most commonly due to dural venous sinus thrombosis[6] and subsequent secondary optic atrophy.

Imaging including angiography may be indicated to identify dural venous sinus thrombosis as a cause of intracranial hypertension and optic atrophy.

[citation needed] According to the International Study Group guidelines, for a patient to be diagnosed with Behçet's disease,[24] the patient must have oral (aphthous) ulcers (any shape, size, or number at least three times in any twelve-month period) along with two of the following four hallmark symptoms:[citation needed] Despite the inclusive criteria set forth by the International Study Group, there are cases where not all the criteria can be met and therefore a diagnosis cannot readily be made.

There is, however, a set of clinical findings that a physician can rely upon in making a tentative diagnosis of the disease; essentially, Behçet's disease does not always follow the International Study Group guidelines and so a high degree of suspicion for a patient who presents having any number of the following findings is necessary:[citation needed] Current treatment is aimed at easing the symptoms, reducing inflammation, and controlling the immune system.

[34] Azathioprine, when used in combination with interferon alpha-2b also shows promise,[35] and colchicine can be useful for treating some genital ulcers, erythema nodosum, and arthritis.

Response to ciclosporin, periocular triamcinolone, and IV methylprednisolone followed by oral prednisone has been reported although relapses leading to irreversible visual loss may occur even with treatment.

[41] Immunosuppressants such as interferon-alpha and tumour necrosis factor antagonists may improve though not completely reverse symptoms of ocular Behçet's disease, which may progress over time despite treatment.

[43][44] A recent 2024 reports that infliximab improved the likelihood of achieving a complete response at 22 weeks for patients with severe Behçet’s syndrome compared to cyclophosphamide, according to head-to-head trial data.

[46] Surgical treatment of arterial manifestations of BD bears many pitfalls since the obliterative endarteritis of vasa vasorum causes thickening of the medial layer and splitting of elastin fibers.

[citation needed] For these reasons, invasive treatment should not be performed in the acute and active phases of the disease when inflammation is at its peak.

The evaluation of disease's activity is usually based on relapsing symptoms, ESR (erythrocyte sedimentation rate), and serum levels of CRP (C-reactive protein).

[citation needed] The syndrome is rare in the United States, Africa and South America, but is common in Asia, suggesting a possible cause endemic to those areas.

[47] A theory suggested that past exposure to lethal infectious agents might have fixed the genetic susceptibility factors to Behçet's disease in those area.

[53] Behçet's can cause male infertility, either as a result of the condition itself or of a side effect of concomitant medication such as colchicine, which is known to lower sperm count.

[54] The first modern formal description of the symptoms was made by H. Planner and F. Remenovsky and published in 1922 in the Archiv für Dermatologie und Syphilis.