Epidemiology
- Most commonly affects individuals from the Mediterranean region to eastern Asia, with the highest prevalence observed in Turkey and Japan
Etiology
- Possible autoimmune and infectious triggers (e.g., precipitating HSV or parvovirus infection)
- Strong HLA-B51 association
Pathophysiology
- Autoimmune systemic vasculitis that can involve arteries and veins of all sizes
- Characterized by the deposition of immune complexes, proliferation of CD4+ T cells, and increased cytokines
Clinical features
- Presents in young adults (20s-40s).
- Classic triad:
- Recurrent, painful oral aphthous ulcers (required for Dx).
- Recurrent, painful genital ulcers.
- Uveitis (anterior or posterior) or retinal vasculitis. Can lead to hypopyon.
- Skin Lesions:
- Erythema nodosum-like lesions (often on shins).
- Papulopustular or acneiform lesions.
- Arthritis: Non-erosive, migratory, oligoarticular arthritis, most often affecting knees and ankles.
- Vascular Manifestations:
- Thrombosis is common (DVT, cerebral venous sinus thrombosis, Budd-Chiari syndrome).
- Aneurysms (especially pulmonary artery).
- Neurologic Manifestations (“Neuro-Behçet’s”):
- Aseptic meningitis or meningoencephalitis.
- Brainstem syndromes, cranial nerve palsies.
Mnemonic
PATHERGY: Positive pathergy test, Aphthous oral ulcers, Thrombosis (arterial and venous), Hemoptysis (pulmonary artery aneurysm), Eye lesions (uveitis, retinal vasculitis), Recurrent Genital ulcers, Young at presentation (3rd decade)
Diagnostics
- Diagnosis is clinical, based on established criteria (International Study Group).
- Requires recurrent oral ulceration PLUS at least two of the following: recurrent genital ulceration, eye lesions, skin lesions, or a positive pathergy test.
- Labs are non-specific but show inflammation (↑ ESR, ↑ CRP).
- No specific autoantibodies are associated with the disease.