| Diffuse idiopathic skeletal hyperostosis | |
|---|---|
| Classification and external resources | |
| OMIM | 106400 |
| DiseasesDB | 4932 |
| eMedicine | article/1258514 article/388973 |
Diffuse idiopathic skeletal hyperostosis (DISH) is a spondyloarthropathy also known as Forestier's disease and ankylosing hyperostosis. It is a noninflammatory disease, with the principal manifestation being calcification and ossification of spinal ligaments and the regions where tendons and ligaments attach to bone (entheses). The whole spine may be involved, and bony ankylosis occurs, although the disc spaces and facet joints remain unaffected. In advanced stages, the disease may look like melted candle wax.[1] The calcification and ossification is almost always restricted to the right side of the spine. In people with dextrocardia and situs inversus this calcification occurs on the left side, which might indicate a role of the mechanical pulsation of the aorta, at least as an aggravating cause.[2]
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The exact cause is unknown. Mechanical factors, dietary and long term use of some antidepressants may be of significance. There is a correlation between these factors but not a cause or affect. The distinctive radiological feature of DISH is the continuous linear calcification along the antero-medial aspect of the thoracic spine. The disease is usually found in people in their 60's and above, and is extremely rare in people in their 40's and 30's. The disease can spread to any joint of the body, affecting the neck, shoulders, ribs, hips, pelvis, knees, ankles, and hands. The disease is not fatal , however some associated complications can lead to death. Complications include paralysis , dysphagia (the inability to swallow), and pulmonary infections. Although DISH manifests in a similar manner to ankylosing spondylitis, these two are totally separate diseases. Ankylosing spondylitis is a genetic disease with identifiable marks, and affects organs. DISH has no indication of a genetic link, and does not affect organs other than the lungs, which is only indirect due to the fusion of the rib cage[3].
Treatment of acne with vitamin derived retinoids was noticed to be associated with similar manifestations in some patients especially with Etretinate[4] which is no longer available for clinical use. other retinoids, like acitretin may cause extraspinal hyperostosis.[5]
DISH may be discovered as a radiological abnormality, as mentioned above, without any symptoms. The usual complaint is with thoracic spinal pain. This occurs in around 80% of patients. Morning stiffness is also noticed in almost two thirds of patients. Increased incidence of dysphagia is also reported in some cases.[6][7] Similar calcification and ossification may be seen at peripheral entheseal sites, including the shoulder, iliac crest, ischial tuberosity, trochanters of the hip, tibial tuberosities, patellae, and bones of the hands and/or feet.[8]
As areas of the spine and tendons can become inflamed NSAIDs such as ibuprofen and Naproxen can be helpful in both relieving pain and inflammation associated with DISH. It is hoped that by minimizing inflammation in these areas, further calcification of tendons and ligaments of the spine leading to bony outgrowths (osteophytes) will be prevented. Physiotherapy to increase spinal range of motion may be beneficial.