Pathologies rares pouvant simuler une spondyloarthrite ou chevaucher avec celle-ci

When a spondyloarthitis is suspected, clinicians have to first identify signs and symptoms from other diseases with similar clinical and imaging features. Identify differential diagnosis has a crucial importance to provide the most appropriate treatment to the patients. In this review, we will examine the clinical signs and imaging features of the disorders, which can mimic or overlap with a spondyloarthritis. We will describe their characteristic symptoms and situations in which we have to think about them. In this review, we will talk about: sacroiliac joint osteoarthritis and osteitis condensans ilii; diffuse and sacroiliac pain in joint hypermobility (Elhers-Danlos); hypo- and hyperparathyroidism; entheseal pain in primary Sjögren's syndrome; sacroiliitis of connective tissue diseases (lupus, etc.) and skeletal manifestations of Behçet's disease, relapsing polychondritis, and sarcoidosis; axial joint involvement of Whipple's disease; rheumatism associated with pityriasis rubra-pilaris; PAPA and PASS syndromes; fibrodysplasia ossificans progressiva; paraneoplastic spondyloarthritis; hypophosphatemia; calcineurin inhibitor-induced pain syndromes (CIPS); skeletal manifestations of fluorosis; pachydermoperiostosis and joint involvement in adult Kawasaki disease.