Behçet disease

Behçet disease is a multisystemic and chronic inflammatory vasculitis of unknown etiology.

Epidemiology

The mean age at which Behçet disease occurs is 20-30 years. The disease is most prevalent in the Mediterranean region, Middle East and East Asia. The highest incidence has been reported in Turkey. Males are affected 2-5 times more often than females.

Associations

• HLA-B51 ⁴

• factor V Leiden mutation ⁴

• superficial thrombophlebitis ⁸

Clinical presentation

The classic clinical triad of Behçet disease consists of:

1. oral ulceration

2. genital ulceration

3. ocular manifestations

Additional clinical manifestations include skin, joints, gastrointestinal tract, genitourinary tract, central nervous system, cardiovascular system, and lung involvement. Vascular complications develop in ~30% (20-40%) of patients with Behçet disease.

Pathology

The underlying pathologic process in Behçet disease is vasculitis, and perivascular inflammatory infiltrates affecting vessels of differing sizes in various organs.

Distribution

Primarily involves four main systems:

• cardiovascular manifestations of Behçet disease

  • affects 5-30% of cases

  • thickening of the aorta and superior vena cava (vasculitis)

  • inflammation of the veins leads to thrombosis while arterial involvement includes arterial narrowing and aneurysmal dilatation

  • pericarditis is the most common cardiac manifestation occurring in 39% of cases ⁹

• thoracic manifestations of Behçet disease

  • affects 1-8% of cases

  • pulmonary arterial aneurysm: fusiform to saccular, commonly multiple and bilateral, located in the lower lobe or main pulmonary arteries (most common pulmonary manifestation of Behçet disease)

  • subpleural alveolar infiltrates, and wedge-shaped or rounded areas of increased density, which represent focal vasculitis and thrombosis resulting in infarction, hemorrhage, and focal atelectasis

• gastrointestinal manifestations of Behçet disease: affects 5-60% of cases

• CNS manifestations of Behçet disease: affects 10-50% of cases

• musculoskeletal manifestations of Behçet disease: >50% develop articular disorders or arthralgia ⁷

Diagnosis

The diagnosis of Behçet disease relies on fulfilling a number of criteria as no single diagnostic test is available ^10,11.

The International criteria for Behcet’s disease assigns one or more ports to a number of criteria, and the likelihood of a diagnosis of Behçet disease increases as the score increases ¹¹.

• ocular lesions: 2 points

• genital aphthosis: 2 points

• oral aphthosis: 2 points

• skin lesions: 1 point

• neurological manifestations: 1 point

• vascular manifestations: 1 point

• positive pathergy test: 1 point

A simple cut off score of 4 or more is sufficient for the diagnosis in the correct clinical setting, however, a more probablistic interpretation of the score is also available ¹¹.

• 0 or 1 = almost certainly not Behçet disease

• 2 = very unlikely

• 3 = possible but unlikely

• 4 = probable

• 5 = highly likely

• ≥ 6 = almost certainly Behçet disease

Treatment and prognosis

The disease may recur, progress, or resolve (either spontaneously, within a few weeks to several months, or with corticosteroid therapy).

History and etymology

It is named after Hulusi Behçet (1889-1948), a Turkish dermatologist.

Differential diagnosis

On imaging consider:

• Hughes-Stovin syndrome