Inflammatory Bowel Disease-related Spondyloarthritis: The Last Unexplored Territory of Rheumatology.

The Spondyloarthritides (SpA) are a group of chronic inflammatory d iseases a ffecting th e spine, peripheral joints and entheses, as well as extra-skeletal structures, including the gastrointestinal tract. On the other hand, inflammatory b owel d isease (IBD), e ither Crohn's d isease o r ulcerative colitis, often affects extra-intestinal sites, including the axial and/or peripheral skeleton. IBD-related arthritis is the type of SpA that occurs in patients affected by IBD, with an incidence up to 50% during the IBD course. Although both manifestations are apparently the result of a common pathogenetic process, physicians often fail to recognize the disease in its entirety: thus, IBD-SpA is managed as two separate diseases, a musculoskeletal and a gastrointestinal one, with a profound impact on patient quality of life. Moreover, the specialty of the treating physician determines the clinical and laboratory tools for disease assessment, which, in turn, guide treatment decisions that may overlook either affected system or even act in the opposite direction. Raising awareness of the intestinal and musculoskeletal manifestations among rheumatologists and gastroenterologists will lead to earlier diagnosis and a multidisciplinary approach, particularly regarding pharmacologic treatments. Given the lack of trial evidence on immunomodulatory drugs in IBD-SpA it is imperative for researchers in both medical disciplines to join efforts, in order to determine referral strategies, appropriate composite measures for disease assessment, treatment algorithms and therapeutic targets.