Clinical features and chronology of clinical manifestations in Behçet's disease: a cohort of 2,615 patients.

Introduction: Behçet's disease (BD) presents with highly variable clinical manifestations and a heterogeneous pattern of symptom development. This study aimed to assess the chronology of symptom onset and clinical findings in BD patients at a nationally recognized Behçet's referral center and to examine associations between symptom progression and patient- and disease-related characteristics. Material and methods: A retrospective review of BD patients from a national referral center in Iran was conducted between March 2007 and March 2017. Patients with ≥ 2 years of follow-up were included. Demographic data, clinical characteristics, and laboratory findings were extracted. The initial symptom and the sequence of symptom development were analyzed. The time between symptom onset and diagnosis was recorded, and comparisons were made based on sex, age, human leukocyte antigen (HLA) type, and initial presenting symptom. Results: A total of 2,615 patients (58.7% male) were included. The mean age at BD diagnosis was 25.0 ±10.1 years, with a median follow-up of 26 years. Oral ulcers were the most common manifestation (98.9% overall) and the most frequent initial symptom (90.3%). Genital ulcers were observed in 61.3% of patients, with a mean onset 4.6 ±5.7 years after diagnosis. Ocular and vascular manifestations had the longest latency from diagnosis. Male patients had a shorter time to onset of oral ulcers ( Conclusions: Our findings highlight substantial temporal heterogeneity in BD symptom progression. While oral ulcers appear early, genital ulcers and skin manifestations tend to develop later, and ocular and vascular lesions exhibit the longest delay. The chronology of symptom onset is significantly influenced by age, sex, HLA-B5/B51 status, and initial presenting symptom. These findings underscore the importance of long-term follow-up in BD management.