Ankylosing Spondylitis

Ankylosing Spondylitis (AS) is a progressive form of arthritis due to chronic inflammation of the joints of the spine. AS cannot be cured, but treatments can improve the symptoms.

Ankylosing Spondylitis Overview

Reviewed: May 8, 2014

Ankylosing spondylitis (AS) is a progressive form of arthritis due to chronic inflammation of the joints of the spine and pelvis. With AS, the spaces between the vertebrae of the spine and between the spine and the pelvis remain swollen and inflamed. This swelling and inflammation causes back pain. AS is a progressive disease and the pain and stiffness associated with the inflammation will eventually limit movement.

AS is an autoimmune disease, but its exact cause is unknown. It is more common in men than in women and it often runs in families. The onset of symptoms of AS usually appear in the late teen or young adult years; most people are diagnosed before the age of 30.

AS cannot be cured, but treatments, including medications and lifestyle modifications, can improve the symptoms.

Ankylosing Spondylitis Symptoms

The symptoms of AS and the disease course vary from person to person.

The hallmark of AS is “sacroiliitis” or inflammation of the sacroiliac joints – the places where the spine meets the pelvis. In the early stages of AS, patients may also experience mild fever, loss of appetite, and general discomfort. Fatigue is also associated with AS. The chronic inflammation can cause anemia, which also contributes to an overall feeling of tiredness and weakness.

In some people, AS can affect joints outside of the spine, such as the shoulders, ribs, hips, knees, and feet. It can also affect the sites where the tendons and ligaments attach to the bones. Rarely, AS affects other organs, such as the eyes, bowel, heart, and lungs.

Almost all cases of AS are characterized by acute, painful episodes (also known as "flares") followed by temporary periods of remission where symptoms subside. Many people with AS have mild episodes of back pain that come and go, but others have severe, ongoing pain and a loss of flexibility of the spine. In severe cases, long-term inflammation leads to calcification that can cause bones of the spine to fuse. Fusion can also stiffen the rib cage, which results in restricted lung capacity and function.

Ankylosing Spondylitis Causes

The cause of AS is unknown. Genetic and environmental factors probably contribute to the disease. AS tends to run in families, and the main gene that has been identified to be associated with susceptibility to AS is called HLA-B27. One theory states that AS starts when the defenses of the intestines start breaking down and bacteria from the intestines pass into the bloodstream directly into the region where the sacroiliac joints are located and cause inflammation.

You have an increased risk of AS if you:

  • Test positive for the HLA-B27 genetic marker
  • Have a family history of AS
  • Have frequent gastrointestinal infections

Ankylosing Spondylitis Diagnosis

To diagnose AS, your doctor will conduct a complete medical and family history, a physical exam, X-rays or MRIs, and blood tests. A rheumatologist is usually the type of doctor who will diagnose and treat AS. Symptom onset and severity varies greatly among individuals, and between men and women, so your doctor will need to rule out other causes of your symptoms before definitively diagnosing AS.

Living With Ankylosing Spondylitis

If you have AS, you will probably see many specialists.

A rheumatologist is trained to treat arthritis and related conditions. An ophthalmologist will treat eye disease or complications related to AS. A gastroenterologist will treat bowel disease. A physiatrist specializes in physical medicine and rehabilitation. A physical therapist will provides stretching and exercise regimens.

A healthy diet and exercise is helpful if you have AS. Although there is no specific diet that is recommended for people with AS, maintaining a healthy weight is important for reducing stress on painful joints. A diet high in omega-3 fatty acids (found in coldwater fish, flax seeds, and walnuts) has been shown to help in reducing joint inflammation in patients with other inflammatory joint diseases. The use of omega-3 fatty acids is not as well studied in people with AS, but there is some evidence that omega-3 supplements could reduce disease activity in people with AS.

Exercise and stretching routines may also ease discomfort and maintain flexibility in painful, stiff joints. Strengthening exercises can build the muscles around painful joints to better support the joints, and range-of-motion exercises improve movement and flexibility and reduce stiffness in the affected joints. Many people with AS find it helpful and comfortable to exercise in water.

Before beginning an exercise program, it is important to speak with a health professional who can recommend appropriate exercises.

Ankylosing Spondylitis Treatments

There is no cure for AS, but some treatments relieve symptoms of the disorder and may delay or prevent its progression. In most cases, treatment involves a combination of medication, exercise, and self-help measures. In some cases, surgery may be used to repair some of the joint damage caused by the disease.

Several medications are used to treat AS, including:

Applying heat to stiff joints and tight muscles can reduce pain and soreness, and applying cold to inflamed areas can help reduce swelling. Hot baths and showers can also provide relief for the symptoms of AS. Massage and using a TENS unit (electrical stimulators for pain) can also provide pain relief.

In severe cases of AS, surgery can be an option in the form of joint replacements, particularly in the knees and hips. Surgical correction is also possible for those with severe deformities of the spine, particularly in the neck.