The simultaneous occurrence of ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH) has been reported in at least 39 cases, but the 2 diseases should not be viewed as mutually exclusive, according to the results of a systematic review published in Rheumatology.1
The investigators sought to review the co-occurrence of AS and DISH in the literature to explore the potential need to revise the current criteria for DISH. AS and DISH are both spinal ankylosing conditions that carry a 4-fold increased risk for spinal fractures, and the most commonly used criteria to diagnose DISH were designed to exclude radiographic signs of spondyloarthritis.
A literature search was conducted to identify full-text articles that discussed the coexistence of AS and DISH in the same patient. A total of 20 articles, including case reports or series of moderate quality, that described the coexistence of AS and DISH in 39 patients were identified.
The researchers note that this number is likely an underestimation of the real number of cases because of publication bias and the strict Resnick criteria for DISH that exclude AS abnormalities. The Resnick criteria for DISH were created to diagnose only a limited spectrum of DISH to distinguish the condition as a separate entity from degenerative spondylosis and AS.2
Overall, neck or back pain was present in 97% of patients (mean age, 61.2% years; 90% men). Moreover, the human leukocyte antigen B27 (HLA-B27) was positive in 9 of 27 documented measurements. There were radiographic abnormalities described in the sacroiliac joint attributable to AS in 82.1% of cases.
If the results of the review are confirmed in a large observational study, revision of the current criteria to include the simultaneous occurrence of AS and DISH should be considered.
- Kuperus JS, Waalwijk JF, Regan EA, et al. Simultaneous occurrence of ankylosing spondylitis and diffuse idiopathic skeletal hyperostosis: a systematic review [published online July 27, 2018]. Rheumatology (Oxford). doi: 10.1093/rheumatology/key211.
- Resnick D, Niwayama G. Radiographic and pathologic features of spinal involvement in diffuse idiopathic skeletal hyperostosis (DISH). Radiology. 1976;119(3):559-568.