Behcet disease is a type of variable vessel vasculitis that most commonly affects young adults (20–40 years of age) from the Mediterranean region to eastern Asia. Patients typically present with recurrent, painful oral and/or genital ulcerations; uveitis and erythema nodosum are also common in patients with Behcet disease. Diagnosis is based on clinical features, but diagnostic studies (e.g., Doppler ultrasound, MRA head) are required to assess for end-organ damage and exclude differential diagnoses (e.g., aphthous stomatitis, reactive arthritis). Management is based on the affected organs and disease severity, but often involves immunosuppressive agents (e.g., glucocorticoids, azathioprine) and colchicine.
Recurrent painful oral aphthous ulcers (95–100%)
- Typically the initial presenting symptom
- Usually last about 1–4 weeks
- Recurrent genital ulcerations (60–90%)
- Ocular disease (50–80%)
Skin lesions (35–85%)
- Erythema nodosum, papulopustular lesions, p, pseudofolliculitis, or acneiform eruptions
- Dermatographism: formation of urticaria after minor pressure is applied to the skin, likely mediated by local histamine release
- Positive pathergy skin test: the appearance of an erythematous papule or pustule 48 hours after a 5 mm skin prick with a 20-gauge needle (usually on the forearm) 
- Arthritis (30–70%)
- Gastrointestinal disease: abdominal pain, anorexia, diarrhea, lower GI bleeding, nausea, vomiting
- Neuro-Behcet syndrome (5–10%) 
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)
General principles 
- Diagnosis is primarily clinical.
- Diagnostic criteria may be used to establish a diagnosis.
- Diagnostic studies may be required to assess for end-organ damage and to exclude differential diagnoses.
Rule out other conditions before starting potentially unnecessary and harmful immunosuppressive therapy.
|International Study Group diagnostic criteria for Behcet disease |
|Mandatory criterion|| |
|A diagnosis may be established in patients who fulfill the mandatory criterion PLUS ≥ 2 of the additional criteria.|
Laboratory studies 
- CBC: leukocytosis
- Inflammatory markers: ↑ ESR, ↑ CRP
- Serology: Autoantibodies (e.g., , , ) are usually absent.
- Genetic studies: HLA-B51 testing is not routinely recommended. 
Imaging studies 
Consider imaging studies based on suspected conditions.
- Doppler ultrasound extremities: VTE and/or arterial aneurysms
- MRI head (with contrast): acute or chronic parenchymal neuro-Behcet
- MRA head: nonparenchymal neuro-Behcet (e.g., , )
- CT and CTA chest or abdomen: large-artery aneurysms and/or thrombosis 
- Endoscopic studies: GI involvement and to rule out alternative diagnoses (e.g., Crohn disease, tuberculosis)
Clinical features of Behcet disease may also be present in several other conditions, e.g.: 
- Aphthous stomatitis, e.g., due to vitamin B12, folate, and/or iron deficiency
- GI diseases, e.g., ,
- Infectious diseases, e.g., tuberculosis, ,
- Rheumatological diseases, e.g., ,
- Dermatological diseases, e.g., Sweet syndrome, ,
The differential diagnoses listed here are not exhaustive.
- Consult a rheumatologist and other specialists as required.
- Choice of therapy is based on the type of lesions.
- Severe disease : Consult a specialist (e.g., neurology, ophthalmology, surgery) and start treatment early to prevent permanent damage. 
- Ocular disease, CNS disease, and/or vasculopathy
- Topical glucocorticoids; (e.g., triamcinolone ) can accelerate the healing of oral and genital ulcers.
- Immunomodulatory agents
- Start pain management.
- Monitor for .
- Consider .