The spondyloarthropathies.

The spondyloarthropathies represent a heterogeneous group of arthropathies including ankylosing spondylitis, reactive arthritis with Reiter syndrome as one subtype, arthritis associated with inflammatory bowel disease, arthritis associated with psoriasis, and juvenile spondyloarthritis. These conditions are linked by several common features: inflammatory arthritis involving the back, a high prevalence of HLA-B27, frequent tendon/ligament insertion inflammation, and several common extra-articular manifestations (iritis, skin lesions). Although not uncommon, these types of arthritis are more difficult to recognize than other types of arthritis such as osteoarthritis and rheumatoid arthritis.