Diffuse Idiopathic Skeletal Hyperostosis (DISH)
Overview
Diffuse idiopathic skeletal hyperostosis (DISH), also called Forestier’s disease, is a form of non‑inflammatory arthritis characterized by the calcification and ossification of ligaments, especially the anterior longitudinal ligament along the spine. This leads to flowing, “candle‑wax”–like bony formations that can be seen on X‑ray.
Who it affects: DISH most commonly appears in adults over 50 years of age, with a marked predilection for males (approximately 2 : 1 male‑to‑female ratio). However, women can develop DISH, particularly after menopause.
Prevalence: Epidemiologic studies estimate DISH in 5–25 % of the population depending on the diagnostic criteria and imaging modality used. In a large cohort of asymptomatic adults undergoing chest CT, the prevalence was ~15 % in men and 9 % in women (Mader et al., 2015). The condition is more frequent in people with metabolic disorders such as obesity and type 2 diabetes.
Although DISH is often discovered incidentally on imaging, a subset of patients develop pain, stiffness, or dysphagia, prompting clinical evaluation.
Symptoms
Symptoms can range from none at all to disabling. The most common manifestations include:
- Back stiffness: Gradual loss of flexibility, especially in the thoracic spine, often worse in the morning.
- Localized pain: Dull, aching pain at the level of the ossified ligaments; can be exacerbated by prolonged standing or twisting.
- Reduced range of motion: Difficulty bending forward or rotating the trunk.
- Difficulty swallowing (dysphagia): Large anterior osteophytes at the cervical spine may compress the esophagus, leading to a sensation of food sticking, coughing, or choking.
- Hoarseness or voice changes: Rarely, compression of the recurrent laryngeal nerve.
- Peripheral enthesopathy: Pain at tendon or ligament insertions (e.g., heel, Achilles) due to ossification of the entheses.
- Thoracic outlet symptoms: Rare compression of nerves or blood vessels in the chest wall.
- Neurologic deficits: Very uncommon, but large ossifications can cause spinal canal narrowing leading to radiculopathy or myelopathy.
Many patients are asymptomatic; the disease is often identified when imaging is performed for another reason.
Causes and Risk Factors
The exact cause of DISH is unknown—hence “idiopathic.” Research suggests a combination of metabolic, mechanical, and genetic factors.
Key risk factors
- Age: Incidence rises sharply after age 50.
- Sex: Male gender is a strong risk factor.
- Metabolic syndrome: Obesity, type 2 diabetes, hyperinsulinemia, and dyslipidemia are consistently associated with DISH (Yoshimura et al., 2018).
- Smoking: Some studies report higher prevalence among current or former smokers.
- Genetics: Familial clustering suggests a hereditary component, though no single gene has been definitively identified.
- Mechanical stress: Repetitive axial loading (e.g., heavy manual labor) may promote ossification.
Pathophysiology (brief)
Abnormal bone formation occurs at the attachment sites of ligaments (entheses). In DISH, the anterior longitudinal ligament undergoes fibro‑osteogenic transformation, leading to flowing osteophytes that bridge adjacent vertebrae. Unlike ankylosing spondylitis, inflammation markers (CRP, ESR) are usually normal, and sacroiliac joints are spared.
Diagnosis
Diagnosis is primarily radiographic, supported by clinical assessment to rule out other spinal disorders.
Imaging studies
- Plain radiographs: Standard lateral thoracic or cervical spine X‑rays reveal characteristic “flowing” osteophytes spanning at least four contiguous vertebral bodies with preserved disc height.
- CT scan: Provides detailed 3‑D view of ossifications, useful for surgical planning or assessing airway compromise.
- MRI: Helpful when neurologic symptoms are present to evaluate the spinal cord or nerve roots; also differentiates DISH from degenerative disc disease.
Diagnostic criteria (Resnick & Niwayama, 1976)
- Flowing ossification along the anterolateral aspect of at least four contiguous vertebral bodies.
- Relative preservation of intervertebral disc height.
- Absence of significant sacroiliac joint erosion, sclerosis, or fusion (to differentiate from ankylosing spondylitis).
Laboratory tests
Blood tests are usually normal but may be ordered to exclude inflammatory arthritis:
- CRP and ESR – typically within normal limits.
- Rheumatoid factor, anti‑CCP – negative.
- Metabolic panel – to assess diabetes, lipid profile.
Treatment Options
There is no cure for DISH; management focuses on symptom control, maintaining mobility, and preventing complications.
Medications
- Analgesics: Acetaminophen or short courses of NSAIDs (ibuprofen, naproxen) for pain flare‑ups. Use NSAIDs cautiously in patients with cardiovascular or renal disease.
- Muscle relaxants: Cyclobenzaprine or tizanidine may help with muscle spasm.
- Neuropathic agents: Gabapentin or pregabalin for radicular pain, if present.
- Bisphosphonates: Not routinely recommended, but some clinicians use them to modulate ectopic bone formation; evidence is limited.
Physical therapy & Lifestyle
- Stretching & strengthening: Gentle range‑of‑motion exercises (e.g., lumbar extension and thoracic rotation) preserve flexibility and reduce stiffness.
- Core stabilization: Strengthening abdominal and back muscles supports the spine.
- Low‑impact aerobic activity: Walking, swimming, or stationary cycling improve circulation without excess axial load.
- Weight management: Reducing BMI lessens mechanical stress and improves metabolic parameters.
Procedural Interventions
- Infiltration injections: Interlaminar or facet joint steroid injections can provide temporary relief for focal pain.
- Osteophyte resection: Surgical removal of large cervical osteophytes is indicated for severe dysphagia, airway obstruction, or refractory pain. Success rates >80 % for symptom improvement, though recurrence can occur.
- Spinal fusion: Rarely required; considered when there is significant instability or neurologic compromise.
Pharmacologic management of comorbidities
Optimizing control of diabetes, hyperlipidemia, and hypertension may slow disease progression and improve overall health.
Living with Diffuse Idiopathic Skeletal Hyperostosis (DISH)
Adapting daily activities and adopting healthy habits can significantly improve quality of life.
- Posture awareness: Use ergonomic chairs, maintain a neutral spine while sitting, and avoid slouching.
- Sleep positioning: Sleep on the side with a pillow between the knees or use a firm mattress to support spinal alignment.
- Heat & cold therapy: Warm showers or heating pads relax tight muscles; ice packs can reduce acute soreness after activity.
- Adaptive equipment: Use reachers for high shelves, long-handled tools, and cushioned mats to prevent falls.
- Regular follow‑up: Annual check‑ins with a primary care physician or rheumatologist to monitor progression and address new symptoms.
- Nutrition: Adequate calcium and vitamin D support bone health, but excessive supplementation is not shown to affect DISH progression.
- Mind‑body techniques: Yoga (modified for limited spinal flexion), tai chi, and mindfulness can reduce perceived pain and improve balance.
Prevention
Because the root cause is unknown, prevention focuses on reducing modifiable risk factors.
- Maintain a healthy weight: Aim for a BMI < 25 kg/m².
- Control metabolic disease: Keep fasting glucose < 100 mg/dL and HbA1c < 6.5 % if possible.
- Quit smoking: Seek cessation programs or nicotine replacement therapy.
- Regular exercise: At least 150 minutes of moderate aerobic activity per week, combined with flexibility work.
- Balanced diet: Emphasize whole grains, lean protein, fruits, and vegetables; limit processed foods high in sucrose and saturated fat.
- Routine medical screening: Early detection of diabetes, hyperlipidemia, or hypertension allows timely intervention.
Complications
If left unmanaged, DISH can lead to several problems:
- Dysphagia or airway obstruction: Large cervical osteophytes may impede swallowing or breathing, especially when lying flat.
- Spinal cord compression: Rare but serious; can cause weakness, numbness, or loss of bowel/bladder control.
- Fractures: Hyperostotic vertebrae become rigid and more prone to fracture after minor trauma, often resulting in unstable injuries.
- Reduced mobility: Progressive stiffness can limit activities of daily living and increase fall risk.
- Secondary ossification: New bone formation at entheses may cause peripheral pain (e.g., heel spur).
When to Seek Emergency Care
- Sudden, severe neck or back pain after a fall or minor injury.
- Weakness, tingling, or numbness in the arms, legs, or trunk.
- Loss of bladder or bowel control (possible myelopathy).
- Difficulty breathing or a sensation of choking that does not improve with sitting upright.
- Rapidly worsening dysphagia with weight loss or dehydration.
References
- Mader JT, et al. “Prevalence of diffuse idiopathic skeletal hyperostosis in a large cohort of patients undergoing chest CT.” *Radiology*. 2015;274(3):714‑720.
- Yoshimura N, et al. “Metabolic factors associated with DISH: a systematic review.” *Arthritis Care & Research*. 2018;70(6):826‑835.
- Resnick D, Niwayama G. “Diffuse idiopathic skeletal hyperostosis (DISH): Forestier’s disease.” *Radiology*. 1976;119(3):559‑566.
- Mayo Clinic. “Diffuse idiopathic skeletal hyperostosis (DISH).” https://www.mayoclinic.org/diseases-conditions/diffuse-idiopathic-skeletal-hyperostosis
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). “Diffuse Idiopathic Skeletal Hyperostosis (DISH).” https://www.niams.nih.gov/health-topics/diffuse-idiopathic-skeletal-hyperostosis
- Cleveland Clinic. “Hyperostosis (DISH) – Symptoms, Diagnosis & Treatment.” https://my.clevelandclinic.org/health/diseases/21571-diffuse-idiopathic-skeletal-hyperostosis-dish
- World Health Organization. “Non‑communicable diseases and metabolic risk factors.” https://www.who.int/news-room/fact-sheets/detail/noncommunicable‑diseases