Table 3.
Differences between DISH and AS.
| Diffuse Idiopathic Skeletal Hyperostosis (DISH) | Ankylosing Spondylitis (AS) | |
|---|---|---|
| Aetiology | Idiopathic | Autoimmune |
| Incidence | 2.9–25.0% | 0.05–1.4% |
| Age of onset | >45 years | <30 years |
| Sex ratio {M/F} | 2:1 | 3:1 |
| Clinical features | Pain, radiculopathy, dysphagia, risk of spinal and peripheral fractures | Pain, spinal stiffness, characteristic postural abnormalities, involvement of large peripheral joints |
| Radiological features | Affects anterior longitudinal ligaments of the spine, spares intervertebral discs and SI joints | Intervertebral joint fusion, especially the SI joints |
| Laboratory investigations | Non-specific and inconclusive | High ESR and CRP Presence of HLA-B27 (in most cases) |
| Associated diseases | Obesity, diabetes mellitus, Hypervitaminosis A | Autoimmune conditions like iritis, uveitis, ulcerative colitis |
| Treatment | Symptomatic | Disease modifying drugs, non-steroidal anti-inflammatory drugs, surgery (occasionally) |