Late-Onset Spondyloarthritis: Subset That Should Not Be Forgotten

Abstract

The spondyloarthritis (SpA) complex embraces ankylosing spondylitis (AS), reactive arthritis (ReA), psoriatic arthritis (PsA), arthritis related to inflammatory bowel disease (IBD), and forms that do not fulfil established criteria, which are labelled as undifferentiated SpA (uSpA)1,2. In the early 1990s, 2 sets of classification criteria were suggested to encompass the clinical spectrum of SpA: the Amor criteria1 and the European Spondylarthropathy Study Group (ESSG)2 criteria. Each form of SpA may have a late onset3,4. The onset of AS, as defined by the modified New York criteria5, is unusual after the age of 50 years. In a population-based descriptive study carried out in Rochester, Minnesota, USA, the total incidence rate of AS was 7.3 per 100,000 person-years and the incidence value after age 55 years was 2.2/100,000 per year6. In a survey of a large number of members of the German Ankylosing Spondylitis Society, only 6% had the beginning of symptoms after age 40 years7. Only a few studies have compared the clinical expression of late-onset disease with that of earlier onset. In 2001, Brophy and Calin examined the influence of age at symptom onset on disease expression as measured by BASRI (Bath AS Radiology index), BASDAI (Bath AS Disease Activity Index), BASFI (Bath AS Functional index), percentage undergoing AS-related surgery, and prevalence of extraarticular manifestations (uveitis, psoriasis, IBD) in patients with earlier onset (before 21 years of age) and late onset (after 30 years of age)8. Age at onset had no significant effect on radiological progression, disease activity, need for non-hip surgical intervention, and prevalence of extraarticular manifestations. In contrast, there was a significant … Address correspondence to Dr. Olivieri. E-mail: ignazioolivieri{at}tiscalinet.it