Diffuse Idiopathic Skeletal Hyperostosis

Diffuse idiopathic skeletal hyperostosis (DISH) is a systemic condition characterized by distinct ossification patterns affecting the spine and peripheral entheses. This condition most commonly affects the spine and is often associated with back pain and stiffness. The term "DISH" was introduced by Resnick et al in 1975 and is now the most widely used term to describe this condition, serving as both an inclusive and descriptive label for the disorder. The underlying pathology of DISH was initially described by Forestier and Rotes-Querol in 1950, based on specimens and a series of 200 patients, referring to the condition as "senile ankylosing hyperostosis." In DISH, ossifications are classically described in the spine as flowing along the anterolateral aspect, involving at least 3 consecutive vertebral levels or 4 contiguous vertebrae. Although less common, peripheral enthesopathy can occur in the shoulders, elbows, knees, or calcaneus. In the spine, DISH most commonly affects the right side of the thoracic spinal segment. The etiology of DISH remains poorly understood, but several risk factors have been identified, including gout, hyperlipidemia, and diabetes. HLA-B8 is commonly found in both DISH and diabetes mellitus. As a result, high rates of diabetes mellitus, hyperuricemia, and hyperlipidemia have been observed in patients with DISH. Unlike other seronegative spondyloarthropathies, no apparent association has been identified between DISH and HLA-B27.