Ankylosing Spondylitis in Iran; Late Diagnosis and Its Causes

Background: Ankylosing spondylitis (AS) is a chronic destructive and inflammatory disease of the axial skeleton manifested by back pain and progressive stiffness of the spine. Objectives: The aim of the present cross-sectional study was to evaluate and identify factors leading to delayed diagnosis of AS in Iranian patients. Patients and Methods: Sixty patients, (53 males, 7 females) with a diagnosis of AS according to the modified New York criteria were recruited. Diagnosis delay was defined as the interval between a patient's first spondyloarthritic symptoms [inflammatory back pain (IBP), inflammatory arthritis, enthesopathy and uveitis] and a correct diagnosis of AS. Results: The average age of patients at diagnosis of AS was 36.4 +/- 4.5 years and the average of delay in diagnosis was 6.2 +/- 3.5 years. The most common diagnosis at the first visit was disc herniation (68.3%). Delay in diagnosis of Human Leukocyte Antigen (HLA-B27) positive and negative patients were 4.6 +/- 2.2 years and 10.1 +/- 3.2 years, respectively (P = 0.0001). Diagnosis delay in patients with morning stiffness and IBP were significantly shorter than that of patients without these symptoms (P = 0.0001 and P = 0.001, respectively). Patients with uveitis had the shortest diagnosis delay (P = 0.02). The Bath Ankylosing spondylitis disease activity index (BASDAI) was not significantly different in early (< 3years) and late (> 3years) diagnosis (3.3 +/- 0.9 and 3.6 +/- 0.7, respectively) (P = 0.18), but the Both ankylosing spondylitis functional index (BASFI) was significantly different between them (3.3 +/- 1.0 and 4.1 +/- 0.7 respectively) (P = 0.001). Conclusions: In this study, delay in diagnosis was similar to other studies. Educating physicians to careful history taking especially in the case of IBP, non-musculoskeletal symptoms such as uveitis and precise physical examination are important in early diagnosis.