Diffuse idiopathic skeletal hyperostosis

Diffuse idiopathic skeletal hyperostosis (DISH) is caused by the build up of calcium salts in the tendons and ligaments (calcification) and abnormal new bone growth (ossification and hyperostosis), but the reason this happens is not understood despite a lot of research. Medical researchers believe the bone formation that is unique to DISH is caused by abnormal growth and activity of bone forming cells (osteoblasts) in the area where tendons and ligaments attach to bone (enthesis). Possible causes of the this bone growth include:

• Mechanical factors, such as repetitive lifting and moving of heavy objects
• Dietary factors, such as long term exposure to high amounts of Vitamin A
• Medications, such as long term use of synthetic vitamin A products or retinoids, most often used to treat severe acne
• Genetic factors, such as a genetic predisposition
• Metabolic conditions, such as diabetes mellitus, acromegaly, and obesity
• Abnormalities of fat derived hormones (possibly leptin) and growth hormones

However, even when an increased risk due to a factor is consistently seen in studies, no one factor has been found to cause DISH by itself. Medical researchers therefore believe DISH is caused by several of these factors working together to cause the abnormal bone growth.

A diagnosis of diffuse idiopathic skeletal hyperostosis (DISH) is often suspected by the signs and symptoms a person has. X-rays can confirm the diagnosis. In some cases, a computed tomography (CT scan) and/or magnetic resonance imaging (MRI) may also be ordered to rule out other diseases that cause the same symptoms. All three types of imaging studies may be used to see which other areas of the skeleton are affected by DISH.

Long-term use of medications called retinoids, such as isotretinoin, which are similar to vitamin A, can increase the risk of diffuse idiopathic skeletal hyperostosis (DISH). It is unclear whether high intake of vitamin A itself increases the risk.

Diffuse idiopathic skeletal hyperostosis is often treated by a rheumatologist. A pain management specialist and/or a physical therapist may also be helpful. In more severe cases that require surgery, an orthopedic surgeon or neurosurgeon may be consulted.

The long-term outlook (prognosis) for people with diffuse idiopathic skeletal hyperostosis (DISH) is usually considered good since it does not lead to a shortened lifespan. However, people with DISH are at risk of certain complications including:

• Chronic pain
• Disability: Loss of range of motion in the affected joint can make it difficult to use that joint.
• Difficulty swallowing: Bone spurs associated with DISH in the neck (cervical spine) can put pressure on the esophagus, making it difficult to swallow or breath during sleep (sleep apnea).
• Paralysis: DISH that affects the ligament running up the outside of the spine (posterior longitudinal ligament) can put pressure on the spinal cord. Spinal cord compression may result in a loss of feeling and paralysis.

Treatment of diffuse idiopathic skeletal hyperostosis (DISH) is focused on the signs and symptoms present in each person. For example, pain caused by DISH is often treated with pain relievers, such as acetaminophen (Tylenol, others) or nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin, others). Severe pain may be treated with corticosteroid injections. Muscle relaxants may also be helpful.

Physical therapy and/or exercise may reduce the stiffness associated with DISH and can help increase range of motion in the joints.

Even though few studies have focused on indications for surgery, it is generally accepted that surgery is indicated for people with severe symptoms (such as airway obstruction and/or dysphagia) in whom medication and therapy approaches have failed.

Visit the following Facebook groups related to Diffuse idiopathic skeletal hyperostosis:
Forestiers/DISH Research
Forestiers/DISH Support