, David G. I. Scott2 and Chetan Mukhtyar2
(1)
Department of Rheumatology, Ipswich Hospital NHS Trust, Ipswich, UK
(2)
Department of Rheumatology, Norfolk and Norwich University Hospital, Norwich, UK
13.1 Introduction
Hulusi Behçet, a dermato-venerologist in Istanbul, described three patients with oral aphthous and genital ulceration along with hypopyon uveitis in 1937. Although he is honored with the eponymous syndrome, it may have been first described in Hippocrates’ third book of endemic diseases in fifth century BC. Benedictos Adamantiades, a Greek ophthalmologist, independently described the syndrome in 1930, and the disease is known as Adamantiades–Behçet’s syndrome in some parts of the world.
13.2 Definition and Classification
There is no recognized definition of this condition. It is generally recognized to be a triad of anterior uveitis usually resulting in a hypopyon, oral aphthous ulceration, and genital ulceration. The International Study Group (ISG) diagnostic criteria are widely used, but have not been formally validated (Table 13.1) [1]. The International Criteria for Behcet’s disease (ICBD) have recently proposed and validated an alternative criteria which are more sensitive but less specific to the ISG criteria (Table 13.2) [2].
Table 13.1
International Study Group diagnostic (classification) criteria for Behçet’s syndrome (1990)
Criteria | Definition |
|---|---|
Recurrent oral ulceration | Minor aphthous, major aphthous, or herpetiform ulceration observed by physician or patient recurring at least three times in one 12-month period |
Plus two of | |
Recurrent genital ulceration | Aphthous ulceration or scarring, observed by physician or patient |
Eye lesions | Anterior uveitis, posterior uveitis, cells in the vitreous on slit-lamp examination, or retinal vasculitis observed by ophthalmologist |
Skin lesions | Erythema nodosum observed by physician or patient, pseudofolliculitis, papulopustular lesions, or acneiform nodules observed by physician in postadolescent patients not on corticosteroids treatment |
Pathergy | Read by physician at 24–48 h |
Table 13.2
International criteria for Behcet’s disease (2014)
Criteria | Points |
|---|---|
Eye lesions | 2 points |
Oral aphthosis | 2 points |
Genital aphthosis | 2 points |
Skin lesions | 1 point |
CNS involvement | 1 point |
Pathergy | 1 point |
13.3 Epidemiology
Behçet’s disease is also known as the ‘silk route disease’ due to its geographical distribution along the overland trading routes from the Far East to Europe by way of the Middle East and the Mediterranean. The prevalence of Behçet’s disease in Turkey is thought to be between 80 and 420 per 100,000 [3]. Behçet’s disease is uncommon in the UK and Northern Europe. The prevalence in Sweden is 4.9 per 100,000 [4]. The usual onset is in the third decade, and although childhood Behçet’s disease has been described, it is rare even in the Mediterranean. There is preponderance of the disease in males. No environmental factors have been associated with Behçet’s disease.
13.4 Etiology
The etiology of Behçet’s disease is unknown, but it is not felt to have an autoimmune pathogenesis. Autoantibodies are not generally found in Behçet’s disease. There is strong association with HLA-B51.
13.5 Clinical Features
The initial symptoms can be nonspecific. BD is a multisystem disease and not all features are apparent at presentation, and therefore, a detailed history with special regard to orogenital ulceration is needed.
13.5.1 Orogenital
Recurrent oral ulceration is usually the first symptom and most patients will have ulceration at some stage of their disease. The ulcers are usually <10 mm in diameter, although the ulcers can be much bigger and herpetiform (Fig. 13.1). They start as erythematous raised circular areas, which develop into circular areas of ulceration. The ulcers have a gray pseudomembrane and surrounding erythema. They are usually localized over the mucosal surfaces, but infrequently can affect the hard palate, tonsils, and pharynx. Major aphthae can heal with scarring, but this rarely causes significant compromise of deglutition.
Figure 13.1
Oral ulceration in Behçet’s disease
Genital ulceration in males is usually scrotal, and infrequently, on the shaft or on the glans penis. In females, the labia majora and minora can be ulcerated. The ulcers usually commence as papules or pustules, which rapidly ulcerate. The ulcers have a punched-out appearance. They can be larger, more painful, and deeper than the oral ulcers. Genital ulcers are resistant to treatment, more likely to get infected, and usually heal with scarring.
13.5.2 Cutaneous
Other skin lesions seen in Behçet’s disease include erythema nodosum, superficial thrombophlebitis, and pyoderma gangrenosum. Acne-like papulopustular lesions are commonly present at the usual areas of acne such as the face, upper chest, and back, but they are only of cosmetic concern. A papulopustular reaction within 48 h of a needle prick is seen in some patients and is termed “pathergy.” This is characteristic of Behçet’s disease and a papulopustular reaction to dermal puncture with a 20G needle has been used for diagnostic purposes (Fig. 13.2). Neutrophilic dermatosis (Sweet’s syndrome) has been reported in Behçet’s disease.
Figure 13.2
Pathergy test in Behçet’s disease – pustule induced by a dermal puncture with a 20G needle
13.5.3 Ophthalmic
The involvement is in the form of panuveitis and retinal vasculitis. The presence of a layer of pus in the anterior chamber (hypopyon) suggests intense inflammation and is associated with an adverse prognosis (Fig. 13.3). Eye involvement is frequently bilateral and appears early within the first few years of the disease. It is rare for individuals to develop de novo eye involvement after the first 5 years [5]. Visual acuity at presentation is worse than 20/40 in 50 %, and 20/200 or worse in 21 % of affected eyes [6]. Recurrent disease flares in the eye result in secondary changes such as cataracts and glaucoma due to the formation of synechiae. Ocular inflammation can continue even after global eye atrophy. Enucleation of the affected eye may be the only way of controlling disease activity in those patients. The common symptoms of eye disease are blurred vision, periorbital pain, photophobia, scleral injection, and excessive lacrimation.
