What does it take to diagnose Behçet disease?

Behçet disease is a systemic inflammatory disease of unknown etiology initially described as a triad of recurrent oral ulcers, genital ulcers, and hypopyon uveitis affecting young male adults. Internationally agreed diagnostic criteria have been proposed to assist in the diagnosis. We present the case of a 26-year-old African-American male who presented with right brachial plexopathy due to axillary aneurysm. Further evaluation revealed the presence of a common carotid artery aneurysm, superior vena cava, and left subclavian vein thrombosis. A few months later, he developed severe bilateral panuveitis with hypopyon, retinal vasculitis, and optic nerve inflammation. Although our patient had no recollection of oral or genital ulcers, the constellation of deep vein thrombosis, multiple arterial aneurysms, bilateral panuveitis, positive pathergy skin test, and elevated inflammatory markers led to the working diagnosis of Behçet disease. Arterial involvement occurs in 3%-5% of patients with Behçet disease and may manifest as either true or false aneurysms. Deep vein thrombosis is the most common venous manifestation and involvement of venae cavae and their tributaries is not uncommon. Anterior and posterior uveitis and retinal vasculitis not only have a prognostic value in Behçet disease but in this particular case supported the diagnosis. In conclusion, incomplete forms of Behçet vasculitis exist and clinicians should be alert to atypical presentations of the disease.