DIAGNOSIS AND DISEASE MONITORING
There is no specific test for Behçets disease, and the diagnosis is based upon clinical criteria.A number of classifications have been formulated, each with its own list of clinical features. In1990, these were amalgamated into the International Study Group Classification criteria (Table 1). These have now been widely adopted, and although intended for the definition of patients participating in research programmes rather than for the diagnosis of individual patients, they also perform well in a clinical context.
Although the diagnosis of Behçets disease may be straightforward once the possibility has been recognized, incomplete disease or unusual presentations often represent a diagnostic challenge.
A detailed clinical history is essential to exclude other conditions and reveal subtle features of this complex disease. Reiters syndrome may be associated with oral and genital ulcers, although the arthritis is generally erosive. Urethritis and sacroileitis are not features of Behçets disease.
Sarcoidosis can also present with erythema nodosum, uveitis and arthralgia, but genital ulcers are not a feature. Chest radiography may be helpful. Stevens-Johnson syndrome also presents with mucocutaneous involvement and conjunctivitis but is not associated with thrombophlebitis, uveitis or arterial disease. There is a considerable clinical overlap between Crohns disease and ulcerative colitis with extragastrointestinal involvement, and Behc¸ets disease with predominantly gastrointestinal involvement. Other causes of periodic fevers, such as familial Mediterranean fever, hyper IgD syndrome or periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome, should be considered in children as recurrent febrile episodes may characterize the onset of Behc¸ets disease. Patients with significant neurological involvement may occasionally be misdiagnosed as having multiple sclerosis. Other chronic systemic diseases associated with recurrent aphthous ulceration include systemic lupus erythematosus and celiac disease. Recurrent orogenital ulceration may also be associated with bullous skin disorders and erythema multiforme.
Laboratory findings are non-specific in
Behçet's disease. Moderate
anaemia of chronic
disease is common, and a neutrophil leukocytosis is seen in 15% of
immunoglobulins may be non-specifically elevated. Autoantibodies
such as rheumatoid
factor, anti-nuclear antibody and anti-neutrophil cytoplasmic
antibody are usually
negative. Importantly, non-specific markers of inflammation such as
level and erythrocyte sedimentation rate can be normal despite
ocular or CNS disease.62 HLA typing is generally not useful in a
because of the lack of sensitivity of the association with HLA-B*51.
My Gratitude to Sara E. Marshall* MB BCh, MRcp (Ire), MRcPath (UK), PhD
Senior Lecturer in Immunology Wright Fleming Institute, Imperial College School of Medicine, London for providing this information