Behçet syndrome

Autoinflammatory vasculitis (variable vessel) of unknown cause, featuring recurrent oral and genital ulcers with eye, skin, and other organ involvement.

• Can cause blindness (severe uveitis) and life-threatening vascular complications in young adults. Unique features (triad of oral/genital ulcers + uveitis, pathergy phenomenon, Silk Road prevalence) make it a favorite on exams.

• Young adult (20–40) often from the historic Silk Road region (Mediterranean, Middle East, Asia) with recurrent painful oral aphthae (canker sores).
• Painful genital ulcers (classically on scrotum or vulva) that heal with scarring.
• Eye involvement – recurrent uveitis (anterior and/or posterior); can cause a hypopyon (layered pus in anterior chamber) and vision loss.
• Skin lesions – erythema nodosum-like tender nodules and acneiform pustules; often a positive pathergy test (sterile pustule 1–2 days after a needle prick).
• Severe cases: thromboses (e.g. DVTs, cerebral venous sinus clot) or neurologic involvement (meningoencephalitis, intracranial hypertension) may occur.

1. Suspect Behçet in patients with ≥3 oral ulcer episodes per year plus systemic findings (genital ulcers, eye or skin lesions) – diagnostic criteria require oral ulcers + ≥2 of those features.
2. Examine for genital scars, uveitis (slit lamp exam), and perform a pathergy test to support the diagnosis.
3. Exclude other causes of recurrent ulcers: test for HSV (viral culture/PCR), evaluate for IBD (Crohn disease), and check autoimmune markers (to rule out SLE).
4. Once diagnosed, assess disease extent: refer to ophthalmology for ocular involvement, and image if vascular symptoms (e.g. MRV for suspected dural sinus thrombosis).

1. For mucocutaneous flares: topical steroids (e.g. mouthwash, creams) for ulcers. Colchicine is often first-line for recurrent oral/genital ulcers and arthritis.
2. Apremilast (PDE-4 inhibitor) is effective at reducing oral ulcer frequency (used in refractory or severe mucocutaneous disease).
3. Ocular, vascular, or CNS disease requires aggressive therapy: high-dose corticosteroids (acute) plus steroid-sparing immunosuppressants (e.g. azathioprine or anti-TNF biologics like infliximab).
4. Thalidomide is an option for refractory ulcers; cyclophosphamide for major vessel aneurysms. For thromboses, immunosuppression is key (anticoagulation is controversial).

• Think "Silk Road": Behçet prevalence is highest from East Asia to the Mediterranean.
• Pathergy phenomenon: minor trauma (needle stick) → exaggerated pustule formation in 24–48h.
• Associated with HLA-B51 (especially in Middle Eastern and Asian patients), though this is not diagnostic.

• Any eye pain, redness, or vision change → urgent ophthalmologic treatment (uveitis can rapidly threaten vision).
• Hemoptysis or sudden respiratory distress in Behçet → suspect pulmonary artery aneurysm (can rupture and cause fatal hemorrhage).
• Severe neurologic symptoms (headache, focal deficits) → evaluate immediately for CNS involvement (e.g. meningoencephalitis or dural sinus thrombosis).

1. Recurrent oral ulcers (≥3/year) → evaluate for Behçet: ask about genital ulcers, eye symptoms, skin lesions; perform pathergy test.
2. If ≥2 other features (genital, ocular, skin/pathergy) are present → criteria met (diagnose Behçet syndrome).
3. If suspicion is high but criteria not fully met, periodically reassess and exclude other causes (HSV, IBD, etc.).
4. Confirmed Behçet → involve specialists per organs (ophthalmology, neurology); treat according to manifestations (local therapy for mild mucocutaneous vs systemic immunosuppression for organ-threatening disease).

• Turkish man in his 30s with recurrent oral and genital ulcers, eye pain/redness (uveitis), and acneiform skin lesions → Behçet syndrome (likely positive pathergy test).
• Patient with a history of Behçet disease presents with new severe headaches and confusion; MRI shows a dural sinus thrombosis → Neuro-Behçet (central nervous system involvement).