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Ankylosing Spondylitis

Definition, Description, Causes and symptoms, Diagnosis, Treatment, Alternative treatment, Prognosis, Prevention

Ankylosing spondylitis (AS) refers to inflammation of the joints in the spine. AS is also known as rheumatoid spondylitis or Marie-Strümpell disease (among other names).


A form of arthritis, AS is characterized by chronic inflammation, causing pain and stiffness of the back, progressing to the chest and neck. Eventually, the whole back may become curved and inflexible if the bones fuse (this is known as "bamboo spine"). AS is a systemic disorder that may involve multiple organs, such as the:

  • eye (causing an inflammation of the iris, or iritis)
  • heart (causing aortic valve disease)
  • lungs
  • skin (causing a scaly skin condition, or psoriasis)
  • gastrointestinal tract (causing inflammation within the small intestine, called ileitis, or inflammation of the large intestine, called colitis)

Less than 1% of the population has AS; however, 20% of AS sufferers have a relative with the disorder.

Causes and symptoms

Genetics play an important role in the disease, but the cause of AS is still unknown. More than 90% of patients have a gene called HLA-B27, but only 10-15% of those who inherit the gene develop the disease. Symptoms of AS include:

  • low back and hip pain and stiffness
  • difficulty expanding the chest
  • pain in the neck, shoulders, knees, and ankles
  • low-grade fever
  • fatigue
  • weight loss

AS is seen most commonly in males 30 years old and older. Initial symptoms are uncommon after the age of 30, although the diagnosis may not be established until after that age. The incidence of AS in Afro-Americans is about 25% of the incidence in Caucasians.


Doctors usually diagnose the disease simply by the patient's report of pain and stiffness. Doctors also review spinal and pelvic x rays since involvement of the hip and pelvic joints is common and may be the first abnormality seen on the x ray. The doctor may also order a blood test to determine the presence of HLA-B27 antigen. When a diagnosis is made, patients may be referred to a rheumatologist, a doctor who specializes in treating arthritis. Patients may also be referred to an orthopedic surgeon, a doctor who can surgically correct joint or bone disorders.


Nonsteroidal anti-inflammatory drugs (NSAIDs), like naproxen (Naprosyn) or indomethacin (Indocin) are used to relieve pain and stiffness. In severe cases, sulfasalazine (Azulfidine), another drug to reduce inflammation, or methotrexate (Rheumatrex), an immune-suppressing drug, is recommended. In cases where chronic therapy is needed, potential drug side effects must be taken into consideration. Corticosteroid drugs are effective in relieving symptoms, but are usually reserved for severe cases that do not improve when NSAIDs are used. To avoid potential side effects, treatment with corticosteroids is usually limited to a short amount of time with a gradual weaning from the drug.

Physical therapists prescribe exercises to prevent a stooped posture and breathing problems when the spine starts to fuse and ribs are affected. Back braces may be used to prevent continued deformity of the spine and ribs. Only in severe cases of deformity is surgery performed to straighten and realign the spine, or to replace knee, shoulder, or hip joints.

Alternative treatment

To reduce inflammation various herbal remedies, including white willow (Salix alba), yarrow (Achillea millefolium), and lobelia (Lobelia inflata), may be helpful. Acupuncture, performed by a trained professional, has helped some patients manage their pain. Homeopathic practitioners may prescribe such remedies as Bryonia and Rhus toxicodendron for pain relief.


There is no cure for AS, and the course of the disease is unpredictable. Generally, AS progresses for about 10 years and then its progression levels off. Most patients can lead normal lives with treatment to control symptoms.


There is no known way to prevent AS.



Brewer Jr., Earl J., and Kathy Cochran Angel. The Arthritis Sourcebook. Los Angeles: Lowell House, 1993.

Swezey, Robert L. Straight Talk on Spondylitis. Spondylitis Association of America, 1994.

Taurog, Joel D., and Peter E. Lipsky. "Ankylosing Spondylitis, Reactive Arthritis, and Undifferentiated Spondyloarthropathy." In Harrison's Principles of Internal Medicine, ed. Anthony S. Fauci, et al. New York: McGraw-Hill, 1997.


Arthritis Foundation.1300 W. Peachtree St., Atlanta, GA 30309. (800) 283-7800. <http://www.arthritis.org>.

National Institute of Arthritis and Musculoskeletal and Skin Diseases Information Clearinghouse. 1 AMS Circle, Bethesda, MD 29892-3675. (301) 495-4484.

Spondylitis Association of America. P.O. Box 5872, Sherman Oaks, CA 91413. (800) 777-8189.


Matsen III, Frederick, ed. "Ankylosing Spondylitis." University of Washington Orthopaedics and Sports Medicine. <http://www.orthop.washington.edu/arthritis/types/ankylosing spondylitis>.

Jeanine Barone, Physiologist


Ankylosing—When bones of a joint are fused, stiff, or rigid.

HLA-B27—An antigen or protein marker on cells that may indicate ankylosing spondylitis.

Immune suppressing—Anything that reduces the activity of the immune system.

Inflammation—A reaction of tissues to disease or injury, often associated with pain and swelling.

Spondylitis—An inflammation of the spine.

Additional topics

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