Late-Onset Axial Spondyloarthritis in an Elderly Patient: A Case Report.

Spondyloarthritis is a group of chronic inflammatory rheumatic diseases characterized by predominant involvement of the axial skeleton (spine and sacroiliac joints) and/or peripheral joints, along with inflammation at sites of tendon and ligament insertion (enthesitis). The disease commonly affects young adults. However, late-onset spondyloarthritis in an elderly patient is a very rare condition, but it can occur. We report a 57-year-old woman admitted to the ​Medicine A Department of Calmette Hospital in April 2026 for two years of chronic inflammatory pain in the left buttock associated with peripheral joint pain. The symptoms meet the full criteria for axial spondyloarthritis, except for the age of the patient. Spondyloarthritis is a chronic inflammatory rheumatic disease that commonly affects young adults, with onset usually before the age of 45 years. Our case highlights the need to re-evaluate the role of the age-at-onset criterion in the Assessment of SpondyloArthritis international Society (ASAS) classification system. While the current criteria perform well in younger populations, rare cases of late-onset spondyloarthritis suggest that some patients may not be adequately captured. Larger epidemiological and validation studies are needed before any modification of the classification criteria can be recommended.