Simultaneous occurrence of diffuse idiopathic skeletal hyperostosis and ankylosing spondylitis

To the best of our knowledge, 10 cases of Ankylosing Spondylitis (AS) and Diffuse Idiopathic Skeletal Hyperostosis (DISH) coexisting in the same patient have been reported. A new case was found in a female patient at Los Angeles Medical Center in 1993, which we report in this paper. We also review the literature (Medline 1970-1994) and analyze the features of the reported cases. In order to study the incidence of this association in our population we have reviewed 106 cases of AS for radiological features of DISH. We found only one case.

this is a rare association with an incidence of 0.94% in our patients with AS. From the known cases, patients showing this association present clinically mild AS in which radiologic findings are the basis for the diagnosis. Finally we question the validity of excluding the diagnosis of DISH in patients with radiological features of sacroiliac ankylosis.