Rheumatologic manifestations are common in Behçet's disease. Joint involvement takes the third place after mucocutaneous and ocular lesions and can be the inaugural manifestation. Monoarthritis and oligoarthritis affect essentially knees and ankles, with a marked male bias. They usually run an acute or recurrent course, with chronic forms being rare. Polyarthritis is not rare and involves the large limb joints and the small joints of the hands and feet. Arthritis in Behçet's disease heels usually without sequelea and the aggressive treatment is not necessary. Unusual forms include arthritis with deformities and/or destruction, pseudogout, rupture of popliteal cyst (imitating deep vein thrombosis) and myositis. The association with spondylarthropathy is not common. Behçet's disease is rarely associated with rheumatoid arthritis, Sjögren's syndrome, systemic lupus erythematosus, relapsing polychondritis and amyloidosis. Children are more likely than adults to have joint manifestations and polyarthritis.
Joint manifestations are common in Behçet's disease. Their unusual forms deserve to be known since they can raise diagnostic problems when they are inaugural.