Ankylosing spondylitis (AS) is a type of arthritis that mainly affects the joints of the spine. Its name is Greek and means “stiffening of a joint”(ankylos) and “vertebrae” (spondylo). The vertebrae are the bones of the spine that, stacked one on top of the other, form the spinal column. Inflammation of the spaces between the vertebrae causes back pain and stiffness.

The hallmark sign of AS is inflammation of the sacroiliac joints, where the base of the spine (the sacrum) meets the pelvis (iliac bone).

AS is a lifelong disease with no cure. The symptoms typically begin in early adulthood and gradually worsen, but severity varies from person to person.

What causes ankylosing spondylitis?

Scientists believe that AS is caused by a combination of genetic and environmental factors. The vast majority of Caucasian people who develop AS have a genetic marker called HLA-B27; however, most people who have HLA-B27 do not develop AS. Also, not everyone who develops AS has the marker and the condition is much less common in some ethnicities. Over 60 genes associated with AS have been identified, so HLA-B27 does not tell the entire story.

The working theory is that an infection, in particular an infection of the gastrointestinal (GI) system, may trigger the inflammation that causes AS in people who are genetically predisposed. People who have had frequent GI infections have a higher risk of developing AS.

How is ankylosing spondylitis diagnosed?

There is no single test that can show that a person has AS, so diagnosis depends on a thorough medical history and physical examination. Most important is the description of symptoms, in particular the nature of the pain and stiffness: Which joints are painful? What makes the pain worse or better (exercise versus rest)? The time of day the pain gets worse? How long has the patient been in pain? Are there other family members with similar joint pain? Has the patient had recent GI illness, or other symptoms such as eye pain or skin rashes?

The most commonly affected joints are the sacroiliac, lower back vertebrae, the cartilage between the breast bone and the ribs, and the hip and shoulder joints. Pain and stiffness in the lower back and hips that is worse in the morning, neck pain, and fatigue are common early signs of the disease. Symptoms often come and go, with flares followed by periods of remission.

What complications can develop?

The long-term inflammation and joint damage that occurs with progressive, severe AS can cause extra bones to form between vertebrae, leading to fusion of the spine. Spinal fusion makes the spine stiff and inflexible and can be debilitating. AS also can lead to compression fractures due to bone weakness, inflammation of the eye (uveitis), and rarely, heart problems. Stiffness and pain in the joints that connect to the rib can make breathing difficult.

How is ankylosing spondylitis treated?

The goal of treatment is to manage pain, prevent or delay progression of the disease, and prevent spinal deformity and other complications, using a combination of medications, exercise, and surgery. Treatment is most effective if it begins before there is irreversible joint damage. Self-care includes staying active, working to maintain good posture, and using heat or cold to ease pain and inflammation.

In general, AS is associated with a normal life expectancy and many patients are able to live fulfilling, productive lives.

Note: Ankylosing Spondylitis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.