Diffuse idiopathic skeletal hyperostosis: Differentiation from ankylosing spondylitis

Abstract

Diffuse idiopathic skeletal hyperostosis (DISH) and ankylosing spondylitis (AS) share involvement of the axial skeleton and peripheral entheses. Both diseases produce bone proliferations in the later phases of their course. Although the aspect of these bone proliferations is dissimilar, confusion of radiologic differential diagnosis between the two diseases exists mostly as a consequence of a lack of awareness of their characteristic clinical and radiographic features. The confusion may extend to the clinical field because both advanced DISH and advanced AS may cause the same limitations of spinal mobility and postural abnormalities. However, the radiologic spinal findings are so different that changes due to each disease can be recognized even in patients in whom both diseases occur. This article reviews the clinical and radiologic characteristics that should help clinicians differentiate between the two diseases without much difficulty.

Imaging Findings Suggestive of Axial Spondyloarthritis in Diffuse Idiopathic Skeletal Hyperostosis

“…The typical radiographic feature of DISH is the presence of flowing ossification along vertebral bodies, mostly found in, but not limited to, the thoracic spine (11). Although their clinical and radiologic results are often pragmatically described as radically opposed, differential diagnosis between DISH and axial SpA might be a challenging issue in clinical practice in certain settings (12). For instance, while DISH is observed mostly in the elderly and axial SpA usually concerns younger adults, DISH can also occur at ages <45 years (13,14).…”

“…Moreover, if DISH can entail spinal pain and stiffness that resemble more mechanical back pain (e.g., due to spondylosis) than axial SpA, some observations have reported typical axial SpA features in DISH patients, such as limitation of spinal mobility and postural abnormalities (15). The SI joint can also be affected by DISH, and this feature could be mistaken for radiographic sacroiliitis (12). Finally, these 2 diseases can coexist in the same patient, making differential diagnosis even more uncertain (16,17).…”

Dr. Mader replies

“…Nevertheless, AS and DISH may, infrequently, co-exist, and occasionally DISH may present with a clinical picture that closely resembles AS. A recent paper addressed the distinguishing features of these 2 entities 6 . The association of DISH with metabolic syndrome, diabetes mellitus, and an increased cardiovascular risk has been recently reiterated 7,8 .…”

Joint fusions in palaeopathology: diagnosis and epidemiology

“…Ligament ossification, such as sacro-iliac ligament ossification may results in sacro-iliac fusion. DISH appears more often in males than females, and the frequency increases in individuals over 40 years of age (Olivieri et al, 2009).…”

“…The left side is typically spared or less involved, which is probably attributable to the pulsating aorta. We have to note that zygapophyseal joint gaps and intervertebral spaces are not affected, the original width of these elements are not usually decreased (Olivieri et al, 2009).…”