Montilla C et al. – The study suggests that age at onset of AS affects the patients’ presenting clinical form. Arthritis of the upper limbs requires a differential diagnosis with other conditions frequent in patients over 50 years of age, such as rheumatoid arthritis or crystal–induced arthropathy.Methods
- The authors studied late–onset AS in the National Registry of Spondyloarthritis of the Spanish Society of Rheumatology (REGISPONSER database) cohort (n = 1257), of whom 3.5% had onset at age ≥ 50 years versus a control group with onset at < 50 years.
- There were no differences between late–onset and early–onset AS according to sex and family history of spondyloarthropathies.
- Patients in the late–onset group more often showed involvement of the cervical spine (22.7% vs 9.7%; p = 0.03) and arthritis of the upper (13.6% vs 3.0%; p = 0.002) and lower limbs (27.3% vs 15.2%; p = 0.03) as first manifestations than did patients in the early–onset group.
- A higher percentage of mixed forms (axial and peripheral joint disease) during the course of the disease was also recorded in the late–onset group (50% vs 24%; p = 0.0001).