Diagnosis of Behçet's disease: clinical characteristics, diagnostic criteria, and differential diagnoses.

BACKGROUND The diagnosis of Behcet disease (BD) is challenging in many cases. The purpose of this study was to describe the clinical characteristics of patients at a referral BD clinic. METHODS In a retrospective study, we collected data from patients at a national referral Behcet clinic from November 2018-August 2019. A BD diagnosis was confirmed (BD group) or ruled out (Non-BD group), and the two groups were compared for differences. RESULTS A total of 238 patients satisfied the inclusion criteria. Forty patients (16.8%) were finally diagnosed with BD. Ocular and genital lesions were significantly more prevalent in the BD group. A positive pathergy test and HLA-B51 were also significantly more common in BD. However, oral lesions, articular involvement, and gastrointestinal manifestations were similar between groups. Also, patients with BD were significantly more likely to have multi-organ (≥2 organ systems) involvement. CONCLUSIONS Being the first study to evaluate the clinical characteristics of patients who are visited at a referral BD clinic and are believed to have a high probability of Behcet, the results of this study are important from an epidemiological standpoint. Also, the findings of this study could be used by referral Behcet clinics, which evaluate and diagnose patients with a high pretest probability and atypical presentations of BD on a daily basis. The alternative diagnoses established in this study could be used as the list of the most common differential diagnoses for Behcet's disease.