BEHÇET SYNDROME

Named after the Turkish dermatologist who first described it, Behçet disease is of unknown cause and most commonly occurs in persons of Asian, Turkish, or Middle Eastern background. The protean manifestations are believed to result from vasculitis that may involve all types of blood vessels: small, medium, and large, on both the arterial and venous side of the circulation.

Behçet’s syndrome is a rare multisystem inflammatory disorder characterized by ulcers affecting the mouth and genitals, various skin lesions, and abnormalities affecting the eyes. Symptoms include mucous membrane lesions of the mouth (canker sores) and genitals (ulcers) that tend to disappear and recur spontaneously. Inflammation of the eyes (anterior uveitis, posterior uveitis, or panuveitis) also affects individuals with Behçet’s syndrome.

Behçet’s syndrome Symptoms and Signs

The hallmark of Behçet disease is painful aphthous ulcer­ati ons in the mouth. These lesions, which usually are mul­tiple, may be found on the tongue, gums, and inner surfaces of the oral cavity.

Genital lesions, similar in appearance, are also common but do not occur in all patients.

Other cutaneous lesions of Behçet disease include tender, erythematous, papular lesions that resemble ery­thema nodosum. (On biopsy, however, many of these lesions are shown to be secondary to vasculitis rather than septal panniculitis.) These erythema nodosum–like lesions have a tendency to ulcerate, a major difference between the lesions of Behçet disease and the erythema nodosum seen in cases of sarcoidosis and inflammatory bowel disease. An erythematous follicular rash that occurs frequently on the upper extremities may be a subtle feature of the disease.

The pathergy phenomenon is frequently underappreci­ated (unless the patient is asked); in this phenomenon, sterile pustules develop at sites where needles have been inserted into the skin (eg, for phlebotomy) in some patients.

A nonerosive arthritis occurs in about two-thirds of patients, most commonly affecting the knees and ankles. Eye involvement may be one of the most devastating com­plications of Behçet disease. Posterior uveitis, in essence a retinal venulitis, may lead to the insidious destruction of large areas of the retina before the patient becomes aware of visual problems.

Anterior uveitis, associated with the triad of photophobia, blurred vision, and a red eye, is intensely symptomatic. This complication may lead to a hypopyon, the accumulation of pus in the anterior chamber. If not treated properly with mydriatic agents to dilate the pupil and corticosteroid eyedrops to diminish inflamma­tion, the anterior uveitis may lead to synechial formation between the iris and lens, resulting in permanent pupillary distortion.

Central nervous system involvement is another cause of major potential morbidity. The central nervous system lesions may mimic multiple sclerosis radiologically. Find­ings include sterile meningitis (recurrent meningeal head­aches associated with a lymphocytic pleocytosis), cranial nerve palsies, seizures, encephalitis, mental disturbances, and spinal cord lesions.

Aphthous ulcerations of the ileum and cecum and other forms of gastrointestinal involvement develop in approximately a quarter of patients.

Large vessel vasculitis can lead to pulmonary artery aneurysms and life-threatening pulmonary hemorrhage.

Finally, patients have a hypercoagulable tendency that may lead to complicated venous thrombotic events, particularly multiple deep venous thrombosis, pulmonary emboli, cerebral sinus thrombosis, and other problems associated with clotting.

The clinical course may be chronic but is often charac­terized by remissions and exacerbations.

Behçet’s syndrome Diagnosis

There are no pathognomonic laboratory features of Behçet disease. Although acute-phase reactants are often elevated, there is no autoantibody or other assay that is distinctive. No markers of hypercoagulability specific to Behçet have been identified.

Behçet’s syndrome Treatment

Both colchicine (0.6 mg once to three times daily orally) and thalidomide (100 mg/day orally) help ameliorate the mucocutaneous findings. Apremilast, a selective phospho­diesterase-4 inhibitor, is effective for the treatment of the oral ulcers.

Corticosteroids (1 mg/kg/day of oral predni­sone) are a mainstay of initial therapy for severe disease manifestations.

Azathioprine (2 mg/kg/day orally) may be an effective steroid-sparing agent.

Infliximab, cyclosporine, or cyclophosphamide is indicated for severe ocular and central nervous system complications of Behçet disease.

LINKS

• https://www.mayoclinic.org/diseases-conditions/behcets-disease/symptoms-causes/syc-20351326
• https://emedicine.medscape.com/article/329099-overview
• https://www.nhs.uk/conditions/behcets-disease/
• https://www.uptodate.com/contents/clinical-manifestations-and-diagnosis-of-behcet-syndrome
• https://my.clevelandclinic.org/health/diseases/12980-behcets-disease
• https://rarediseases.org/rare-diseases/behcets-syndrome/