1. Take the Ankylosing Spondylitis Quiz
2. Myths and Facts About Back Pain

Medical Author:

Jason C. Eck, DO, MS

Jason C. Eck, DO, MS

Dr. Eck received a Bachelor of Science degree from the Catholic University of America in Biomedical Engineering, followed by a Master of Science degree in Biomedical Engineering from Marquette University. Following this he worked as a research engineer

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Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Patients with AS develop low back pain, hip pain, and stiffness, or both. Later, patients develop upper back pain and pain in the ribs. Symptoms most commonly begin in late adolescence, and males are three times more likely to develop ankylosing spondylitis than females. It is uncommon for patients over 45 years old to develop AS. If symptoms begin in those younger than 16 years, the disease is termed juvenile-onset ankylosing spondylitis, which is more common in Native Americans and in people who live in developing countries.

People with ankylosing spondylitis generally complain of back pain of gradual onset that may not become apparent until the condition is well established. The pain progresses with a series of flare-ups and remissions. The back pain is dull and is felt in the hips and buttocks. The pain often begins on one side (unilateral) and comes and goes (intermittent), but as the disease progresses, it becomes more persistent and affects both sides (bilateral).

Key components of a person's medical history that suggest ankylosing spondylitis include the following:

• Gradual onset of low back pain



• Onset of symptoms prior to age 40 years



• Presence of symptoms for more than three months



• Symptoms worse in the morning or with inactivity



• Improvement of symptoms (especially morning stiffness) with exercise

Involvement of the hips and shoulder joints is possible but is more common in juvenile-onset ankylosing spondylitis (patients with onset before age 16 years).

Involvement of the jaw (temporomandibular joint, TMJ) can lead to decreased range of motion in the jaw and occurs in approximately 10% of people with ankylosing spondylitis.

Involvement of the ribs can lead to decreased range of motion of the chest wall and difficulty expanding the lungs during breathing.

Long-term involvement of the spine eventually leads to a progressive decrease in range of motion. Eventually, the bones of the spine grow together and prevent any motion in the affected bones of the back and neck. Involvement of the neck (cervical spine) and upper back (thoracic spine) can lead to fusion of the neck in a downward position (forward flexed) . Fusion of the neck in this position can significantly limit a person's ability to walk because of an inability to look straight ahead or to drive a car without adaptive mirrors because of difficulty turning the head.

Other complications include the following:

• Inflammation of the iris, the colored part of the eye (acute iritis): Acute iritis occurs in 25-30% of people with ankylosing spondylitis and generally only affects one eye. Symptoms include pain, increased tearing (lacrimation), sensitivity to light (photophobia), and blurred vision.



• Inflammation of the aorta, the major blood vessel from the heart (aortitis) and stiffening of the blood vessels (aortic fibrosis): Involvement of the heart is generally occurs in patients that have had AS for a long time. Severe cases can lead to complete heart block or weakening of the aortic valve (aortic valve insufficiency).



• Stiffening of the lungs (pulmonary fibrosis): Involvement of the lungs is caused by stiffening of the rib joints that limits range of motion of the chest wall. Pulmonary fibrosis generally produces no symptoms. If a chest x-ray film is obtained for another reason, pulmonary fibrosis is a finding that may also show up on the film.



• Decreased function of the brain, spinal cord, muscles, and nerves (neurologic deficit): Neurologic deficits can be caused by spinal fracture or cauda equina syndrome due to narrowing of the spinal canal (spinal stenosis). Spinal fracture is most common in the neck (cervical spine).

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