Enteropathic arthritis, uveitis, Whipple's disease, and miscellaneous spondyloarthropathies.

Enteropathic arthritides, uveitis, and Whipple's disease all belong to the category of spondyloarthropathies. The exact mechanism of relationships among joint, tendon, and axial involvement in the spondyloarthropathies, and gut and eye involvement, is unsolved. Different hypotheses have been proposed to explain the role of enterogenic bacteria in interfering with the HLA system and causing inflammatory reactions in these organs. The microorganism responsible for Whipple's disease (Tropheryma whippelii) has been identified by sequencing the largest part of a bacterial 16S ribosomal RNA, followed by polymerase chain reaction amplification. Late-onset pauciarticular juvenile chronic arthritis should be included in the category of the spondyloarthropathies. New cases of ankylosing spondylitis associated with diffuse idiopathic skeletal hyperostosis have been reported.