What Is Diffuse Idiopathic Skeletal Hyperostosis?
Diffuse idiopathic skeletal hyperostosis is a disorder in which bone forms on areas where it should not. In particular, bone forms most frequently at areas where ligaments (e.g. cords connecting two bones) connect the bones of the spine (e.g. entheseal areas) . Bone can also form in other areas and on other types of connective tissues like tendons (e.g. cords attaching muscle and bone). Bone may grow excessively in other areas of the skeleton including the shoulders, elbows, hips, knees, ankles, feet, hands, and ribs.
This condition may cause no symptoms whatsoever, or it may cause mild to moderate stiffness or pain in the thoracic spine (e.g. upper back) that generally gets worse over time and can become severe and debilitating. Other symptoms include difficulty swallowing or hoarseness, spinal fractures, and tingling or numbness in the lower legs or even paralysis .
Treatment focuses on addressing overall health to limit the progression of the disease as well as supportive measures for specific symptoms.
You should visit your primary care physician who will be able to confirm the diagnosis with X-ray, and localize the problem to specific areas in your spine. This disease is managed with pain medication, physiotherapy, and, in rare cases, surgery.
How common is diffuse idiopathic skeletal hyperostosis?
Diffuse idiopathic skeletal hyperostosis is also known as
- Forestier’s Disease
Diffuse Idiopathic Skeletal Hyperostosis Symptoms
The main symptoms of diffuse idiopathic skeletal hyperostosis include the following.
- Stiffness/Loss of range of motion: Stiffness is usually worse in the morning and it is typical to experience a loss of range of motion in the back. During sleep, you move less than when you’re awake and the joints of the spine can become mildly inflamed. Swelling can limit the ability of the spine to move until it is disrupted by movement upon waking. It is common for this stiffness to recur as movement subsides in the evening.
- Pain: Pain is most common in the neck or upper back of the spine. Pain may also occur in the shoulders, elbows, knees, or heels. Pain has also occasionally been reported to occur prior to the development of changes on X-ray. It can occur at rest but may also occur when pressure is applied to any of the affected body parts. It is undetermined whether the pain occurs because of inflammation or chronic bone changes and bone growth over time.
Other possible symptoms of diffuse idiopathic skeletal hyperostosis include the following.
- Difficulty swallowing or hoarse voice: Hoarse voice can occur if one of the outgrowths of bone (e.g. bone spurs) presses upon one of the nerves that allow the vocal cords to move (e.g. laryngeal/recurrent laryngeal nerve). Hoarse voices can also occur if outgrowths compress the esophagus, thus limiting and adjusting the outflow of air from the esophagus. It is also known to cause stridor (a harsh, grating sound), inhaling of particles like food or saliva into the lungs (aspiration), and dislocation of joints in the upper portion of the spine.
- Spinal fracture: During advanced diffuse idiopathic spinal hyperostosis, the hardened (e.g. ossified) ligaments of the vertebrae of the spine become unable to bear the pulling and stretching forces applied because the addition of bone makes ligaments less pliable and makes bones less able to move together. This causes fractures in the spine of a person with DISH where a person without the disease might have normal movement of the spine.
- Tingling or numbness in lower legs/Paralysis: Tingling or numbness can occur if a bone spur impinges upon one of the nerves of the lower back. If the bone causes damage to the spinal cord in extreme cases, it can also cause paralysis (e.g. loss of motion or sensation along all four limbs). Most commonly, impingement of the spinal cord occurs in people of Asian descent . Prior to the loss of function, symptoms may cause sharp pain along the neck.
Diffuse Idiopathic Skeletal Hyperostosis Causes
Diffuse idiopathic skeletal hyperostosis does not yet have a definite and identified cause. It is known, however, that it develops through a process of calcium build-up along the tendons and ligaments of the body concurrently with abnormal bone growth and excess bone growth — in both unexpected and expected places (ossification and hyperostosis). It is believed that this calcification is caused by cells that form bone, called osteoblasts, that for unknown reasons begin to develop and construct bone in places that it should not be.
Who is most likely to be affected
Diffuse idiopathic skeletal hyperostosis is more common in the following groups .
- Individuals over the age of 50
- Individuals with conditions that elevate the level of insulin in the body: Such as type 2 diabetes, prediabetes, obesity, and hyperinsulinemia.
- Individuals who take certain medications: This condition may also be aggravated by certain medications that are similar in structure to vitamin A, called retinoids (isotretinoin) .
- Pima Indian lineage: The risk of developing the disease is thought to be elevated among people of this heritage.
Treatment Options and Prevention
There is no cure for diffuse idiopathic skeletal hyperostosis. Treatment currently focuses on stopping the progression of the disease and relieving pain from the symptoms.
Exercise and physical therapy
There are no major studies that confirm this but many physicians who treat diffuse idiopathic skeletal hyperostosis and many people with the disease report that gentle exercises can improve the symptoms . Beneficial exercises may include those that target range of motion or general stretching as well as function exercises to increase strength and mobility. Aerobic or cardio exercises are known to increase endurance. Many people report that swimming is an ideal type of exercise as it is low impact and minimizes the risk of fracture and helps flexibility, endurance, and pain .
Heating, including heating pads, hot water bottles, and heating patches have been known to increase and assist in minimizing pain and mobility. Conversely, cold can worsen pain, flexibility, and mobility.
Weight and blood sugar control
Because elevated levels of insulin are known to aggravate both the symptoms and the progression of diffuse idiopathic skeletal hyperostosis, if an individual has type II diabetes or hyperinsulinemia, better management of glucose and insulin levels can significantly improve symptoms and slow down the progression of the disease. Weight control can be managed with the assistance of a nutritionist, physical trainer, or physician.
For bone spurs in the heels, pain and deformity can be managed using custom orthotics. Orthotics of this type must often be developed by a podiatrist.
Because the pain is inflammatory, often non-steroidal anti-inflammatories (NSAIDs) are the most effective drugs to help manage the pain occurring due to diffuse idiopathic skeletal hyperostosis. Most frequently, mild pain is treated with over-the-counter pain medications like acetaminophen (Tylenol). Joint pain can be treated most often using NSAIDs such as ibuprofen (Advil, Motrin). Finally, the steroid injections have been used at particularly painful joints and insertions of the ligaments.
Surgery is an infrequent treatment for diffuse idiopathic skeletal hyperostosis. There are a handful of disorders that necessitate surgical intervention. When spurs develop and cause dysphagia or difficulty swallowing, this is an indication for surgery in most people. There is a ligament in the spine that predisposes people to experience the loss of motion or loss of feeling in the limbs when it calcifies. Additionally, if the nerve root is compressed, it can cause a life-threatening condition known as thoracic outlet syndrome.
When to Seek Further Consultation
Diffuse idiopathic skeletal hyperostosis is not a life-threatening condition in most cases. You should seek further consultation if the pain or stiffness become debilitating and disabling. Major risks presented by diffuse idiopathic skeletal hyperostosis include paralysis (e.g. loss of movement of the limbs) paresis (e.g. loss of sensation in the limbs) and difficulty swallowing or an inability to protect one’s airway from saliva or particles that may cause infection or damage to the lungs.
Questions Your Doctor May Ask to Diagnose
To diagnose this condition, your doctor would likely ask about the following symptoms and risk factors.
- How long have you been experiencing back pain?
- Does your back pain radiate anywhere?
- Do your symptoms get worse when you exercise?
- Have you been experiencing a deep, aching bone pain that started for no apparent reason?
- What makes your back pain worse?
The above questions are also covered by our A.I. Health Assistant.
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- Diffuse idiopathic skeletal hyperostosis: Diagnosis & treatment. The Mayo Clinic. Oct. 26, 2018. Mayo Clinic Link