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Behcet’s Disease

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Overview

Behçet’s disease is a multi-system disorder of unknown aetiology characterised by recurrent oral ulcers and is presumed to be an autoimmune disease. It involves the mucocutaneous, ocular, cardiovascular, renal, gastrointestinal, pulmonary, vascular, musculoskeletal, urological, and central nervous systems. In many patients, disease activity decreases with time.

Epidemiology

  • Most common in the Middle East, Mediterranean, and Eastern Asia
  • Males and females are equally affected, but men tend to have a more active and severe form of the disease
  • An age of onset younger than 25 years is associated with a higher prevalence of eye disease and active clinical disease

Risk Factors & Associations

  • Family history
  • Age 20-40 years
  • HLA-B51

Presentation

The classic history consists of oral ulcers, genital ulcers, and anterior uveitis. Features include:

  • Skin manifestations:
    • Acne in atypical areas e.g. the arms and legs
    • Erythema nodosum
  • Musculoskeletal manifestations:
    • Arthritis
  • Vascular manifestations:
  • Gastrointestinal manifestations:
    • Abdominal pain
    • Diarrhoea
    • Gastrointestinal ulceration – may present with features similar to inflammatory bowel syndrome
  • Respiratory manifestations – may suggest pulmonary aneurysm:
  • Neurological manifestations:

Differential Diagnoses

Herpes simplex infection

  • Other features of herpes simplex present
  • Oral ulcers are usually on the outer part of the lips, not just the mucosal surface

Inflammatory bowel disease

  • Genital ulcers and eye involvement less common
  • Rectal or anal pathology (such as fistulae) are more common

Investigations

Overview

  • Pathergy testing:
    • Subcutaneous skin prick with a sterile needle shows induration with or without a pustule within 48 hours
  • Autoantibodies – to screen for other autoimmune disorders:

Other tests are used depending on the presentation:

  • Lumbar puncture:
    • Indicated when neurological involvement suspected
  • MRI brain with contrast:
    • When large phlebitis or CNS involvement suspected
  • Colonoscopy:
    • When gastrointestinal symptoms are present
  • Upper GI endoscopy:
    • When gastrointestinal symptoms are present
  • CT chest, CT angiography of the chest, and pulmonary angiography:
    • If a pulmonary aneurysm suspected

Diagnosis

Patients have recurrent oral ulcers and two of the following in the absence of other systemic diseases:

  • Recurrent genital ulceration
  • Skin lesions are seen by a physician in an adult not receiving corticosteroids
  • Eye involvement (uveitis/retinitis) observed by an ophthalmologist
  • Positive pathergy test interpreted by a physician at 48 hours

Management

In mucocutaneous ulcers:

  • 1st line: topical or oral corticosteroids e.g. triamcinolone paste
  • 2nd line: colchicine or oral corticosteroid or immunosuppression therapy
  • 3rd line: TNF inhibitors

Eye, GIT, CNS and vascular involvement involve the use of prednisolone and anticoagulation in vascular involvement.

Any new manifestations involving the eye, CNS, or vascular system should involve prompt referral to the corresponding specialty. 

Patient Advice

  • Patients should be aware of new visual changes, mental state changes, lower extremity swelling or haemoptysis and should seek urgent medical help if they manifest.

Complications

  • Blindness – untreated eye involvement can lead to blindness in 5 years
  • Increased risk of malignancy due to long-term immunosuppression use
  • Pulmonary aneurysm formation
  • Central nervous system involvement
  • Vasculitis

Prognosis

  • There is a variable course of flareups and remissions lasting for years
  • Men tend to have a worse prognosis
  • Prognosis depends on the system involved
  • Death is usually secondary to CNS involvement, vascular disease, bowel perforation, cardiorespiratory disease, or complications with immunosuppressive therapy.

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