Spondyloarthritis (SpA) is a chronic inflammatory disease1 encompassing several previously nosologically defined rheumatologic entities (ankylosing spondylitis, reactive arthritis, psoriatic arthritis, inflammatory bowel disease-associated arthritis, undifferentiated spondyloarthritis), with a new terminology2,3. These conditions share common features in the rheumatologic domain (predominant and frequent axial involvement, enthesitic involvement, possibility of dactylitis) and in the immunogenetic domain (HLA-B27, endoplasmic reticulum aminopeptidase-1, or interleukin 23R polymorphisms). They also share extraarticular manifestations: psoriasis, uveitis, and inflammatory bowel diseases (IBD). These extraarticular manifestations are important to consider. They may help to diagnose SpA, and in a case of inflammatory back pain, presence or history of anterior uveitis (AU), psoriasis, or IBD is crucial for the clinical certainty of the diagnosis. Logically, they are part of the several classification criteria for SpA4. They are also to be considered at a therapeutic decision level; for example, coexistence of active IBD should prompt the clinician, in case of indication of a tumor necrosis factor (TNF) blocker for SpA, to favor a monoclonal antibody rather than a soluble receptor5. These extraarticular features also represent the most frequent expression of the so-called “paradoxical” effects of …
Address correspondence to Prof. D. Wendling, Department of Rheumatology, CHRU Besançon, Boulevard Fleming, 25030 Besançon, France. E-mail: dwendling{at}chu-besancon.fr