Ankylosing Spondylitis Characteristics

By: Judith Frank, MD
March 6, 2008

Unfortunately the origins of ankylosing spondylitis are not well understood, but genes and heredity play an important role. A gene called HLA-B27 is found in more than 90% of people with ankylosing spondylitis. This form of arthritis is much more prevalent in males, and generally is diagnosed before they reach the age of 30.

Ankylosing spondylitis often occurs in the teens or early 20s
This form of arthritis generally affects young adults, commonly beginning before patients are 35 years old. The average age at diagnosis is 24, although children - as well as older patients - have also been diagnosed with varying stages of the disease.

Ankylosing spondylitis occurs more often in males
Ankylosing spondylitis is diagnosed more often in men, who also tend to have more severe symptoms. Some professionals believe that the disease may actually be equally prevalent in both genders but diagnosis is often overlooked or missed in women because they tend to have pain in peripheral joints, such as the neck or hips, as well as the back.

Patients with crippling joint pain caused by severe cases of ankylosing spondylitis tend to have several distinctive characteristics:

• A ‘curled forward’ posture - the chin-to-chest stance - which results in a persistent downward gaze
• Brittle bones in the spine that are prone to fractures
• Significantly limited mobility and movement, such that the patient is permanently disabled

f the disease progresses from the low back all the way up the spinal column, patients are at risk of developing significant complications that can increase the pain and disability already experienced. Potential complications include:

• Cauda Equina syndrome, which can cause pervasive extremity numbness, weakness and bowel or bladder dysfunction
• Spondylodiscitis, an inflammation of the intervertebral disc caused by the hardening of the fibrous tissue that encompasses the disc
• Limited chest expansion, which may impact the ability to breathe freely

These complications are quite rare and are generally only seen in the most severe cases of ankylosing spondylitis.

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