Spondyloarthritis is not the inevitable destination.
Reference1. Wang R, Crowson CS, Wright K, Ward MM. Clinical evolution of patients with new-onset inflammatory back pain: a population-based cohort study. Arthritis Rheumatol. 2018 Feb 22. doi: 10.1002/art.40460. [Epub ahead of print]
Inflammatory back pain (IBP) is characterized by gradual onset in young adults with associated morning stiffness and improvement with activity. Both the New York criteria for ankylosing spondylitis (AS) and the Assessment of Spondyloarthritis International Society (ASAS) classification require the presence of IBP.
The Calin, Berlin, and ASAS criteria for IBP have specificities for a diagnosis of SpA that range from 72% to 91.7%.
The researchers sought to include patients seen by specialists as well as those seen in primary care offices and took this into account when designing the study.
Development of SpA was determined by the AS modified New York criteria or by a clinical diagnosis of spondyloarthritis, psoriatic arthritis, inflammatory bowel disease-associated arthritis, or reactive arthritis.
Ninety-two percent of the cohort fulfilled the Calin criteria, 28% fulfilled the Berlin criteria, and 48% fulfilled the ASAS criteria for IBP. The probabilities that patients with IBP would develop SpA at 5, 10, and 15 years were 24% (95% confidence interval [95% CI]: 16-31), 30% (95% CI: 21-37), and 33% (95% CI: 24-42), respectively. The probabilities that symptoms of IBP would resolve at 5, 10, and 15 years were 19% (95% CI: 12-26), 43% (95% CI: 34-52), and 49% (95% CI: 39-57), respectively.
Patients with history of uveitis had a 5-fold higher risk of developing SpA compared with those without a history of uveitis (hazard ratio [HR]: 5.0; 95% CI: 2.5-10.2). Men without uveitis had a 2.7-fold higher risk of SpA compared with women (HR: 2.7; 95% CI: 1.0-7.1). In men with no personal history of uveitis, a family history of SpA increased the risk of developing SpA by 3.2-fold compared with men without a family history (HR: 3.2; 95% CI: 1.3-8.1).
The symptoms of IBP may represent a self-limited process. In addition, IBP may be a part of a broad differential diagnosis.
Be careful not to overinterpret the implications of a IBP diagnosis. IBP is not a predestination to SpA.
