Spondyloarthropathies.

The spondyloarthropathies are disorders characterised mainly by sacroiliitis (with or without spondylitis), peripheral oligoarthritis, enthesopathy, absence of rheumatoid factor, certain extra-articular features such as iritis, and increased prevalence of HLA-B27. The diagnosis should be considered in patients, especially young people, with low back pain. A history of psoriasis, bowel dysfunction, eye problems and peripheral joint inflammation should point to the diagnosis.