Clinical case
A 26-year-old man presents to the dental clinic with a history of recurrent painful mouth ulcers for several years. The ulcers occur every few weeks and make eating acidic or spicy foods difficult. He reports that he has also had painful genital ulcers and episodes of red, painful eyes with blurred vision. On examination, there are several round, shallow ulcers on the non-keratinised oral mucosa with yellow bases and erythematous margins. He also has tender nodular lesions on his shins.
Pathophysiology
The exact cause of Behçet’s disease is unknown. It is thought to result from abnormal immune activation in genetically predisposed individuals, probably triggered by environmental or infectious factors.
Key mechanisms include:
Variable-vessel vasculitis affecting arteries and veins.
Neutrophil hyper-reactivity and exaggerated inflammatory responses.
Autoinflammatory and autoimmune features, rather than a purely antibody-mediated autoimmune disease.
Genetic susceptibility, especially HLA-B51, which is associated with increased risk and more severe disease in some populations, but is not diagnostic.
Possible environmental or microbial triggers, although no single causative organism has been confirmed.
The oral ulcers resemble recurrent aphthous stomatitis clinically and histologically, but in Behçet’s disease they occur as part of a wider systemic inflammatory condition.
Epidemiology and Risk Factors
Behçet’s disease is rare in the UK and northern Europe but more common in populations from the historical “Silk Road” regions, including Turkey, the Middle East, Central Asia, East Asia and Japan.
Non-modifiable | Modifiable |
|---|---|
Age: typically presents between 20-40 | Smoking |
Ethnicity: more common in people from Turkey, the Middle East and Asia | Oral trauma |
Poor oral hygiene |
Clinical Features
Symptoms | Signs | |
|---|---|---|
Major criteria | Oral aphthosis | Uveitis |
Genital aphthosis | Retinal vasculitis | |
Ocular lesions | Erythema nodosum-like lesions | |
Minor criteria | Skin lesions | Papulopustular lesions |
Neurological symptoms | Meningoencephalitis-like presentation | |
Vascular symptoms (e.g. limb swelling, haemoptysis) | Thrombophlebitis or thrombosis | |
Investigations
Behçet's disease is primarily a clinical diagnosis and there is no single definitive test. There are two main diagnostic criteria for Behçet's disease, the NHS criteria and the International Criteria for Behçet's disease.
NHS criteria:
At least three episodes of mouth ulcers over the past 12 months and you have at least two of the following symptoms:
genital ulcers
eye inflammation
skin lesions (any unusual growths or abnormalities that develop on the skin)
pathergy (hypersensitive skin)
International Criteria for Behçet's disease:
Oral aphthosis, genital apotheosis and ocular lesions are given 2 points (major criteria from the above table), with 1 point for skin lesions, neurological manifestations and vascular manifestations (minor criteria from the above table).
A score of 4 or more points is classified as having Behçet's disease.