Ankylosing Spondylitis

What is ankylosing spondylitis?

Ankylosing spondylitis is a form of chronic inflammation of the spine and the sacroiliac joints. The sacroiliac joints are located in the low back where the sacrum (the bone directly above the tailbone) meets the iliac bones (bones on either side of the upper buttocks). Chronic inflammation in these areas causes pain and stiffness in and around the spine. Over time, chronic spinal inflammation (spondylitis) can lead to a complete cementing together (fusion) of the vertebrae, a process referred to as ankylosis. Ankylosis leads to loss of mobility of the spine.
Ankylosing spondylitis is also a systemic disease, meaning it can affect other tissues throughout the body. Accordingly, it can cause inflammation in or injury to other joints away from the spine, as well as to other organs, such as the eyes, heart, lungs, and kidneys. Ankylosing spondylitis shares many features with several other arthritis conditions, such as psoriatic arthritis, reactive arthritis, and arthritis associated with Crohn's disease and ulcerative colitis. Each of these arthritic conditions can cause disease and inflammation in the spine, other joints, eyes, skin, mouth, and various organs. In view of their similarities and tendency to cause inflammation of the spine, these conditions are collectively referred to as "spondyloarthropathies." Ankylosing spondylitis is considered one of the many rheumatic diseases because it can cause symptoms involving muscles and joints.
Ankylosing spondylitis is two to three times more common in males than in females. In women, joints away from the spine are more frequently affected than in men. Ankylosing spondylitis affects all age groups, including children. The most common age of onset of symptoms is in the second and third decades of life.

HOW DO YOU KNOW IF YOU HAVE ANKYLOSING SPONDYLITIS?                                         Seventy-five percent of patients with ankylosing spondylitis most commonly complain of lower back pain. 

Although lower back pain is a common complaint overall and can be caused by many other factors, back painassociated with ankylosing spondylitis is unique in part because of the following features:

-       Disease starts in early adulthood, often before 40 years of age.

-       Gradual onset of symptoms rather than a history of sudden onset such as after an injury

-       Symptoms persist for three months or longer.

-       Pain is worse after rest or prolonged sitting, such as pain upon waking in the morning.

-       Pain improves with activity and exercise. 

-       Rib cage pain; especially while taking a deep breath or coughing.

-       Stiffness or decreased movement of the back and neck. Ordinary tasks such as putting on sock and shoes may become difficult and painful. AS is an inflammatory process that involves other  areas of the body in addition to bones, including the eyes and spinal cord. 

Eyes — Uveitis, or inflammation of part of the eye, occurs in 25-40% of patients with AS. Symptoms of uveitis include sudden onset of severe eye pain, blurring of vision and difficulty tolerating bright light.  Uveitis requires immediate medical attention and treatment.

Spinal Cord — Vertebrae, or bones of the spine, serve as the structural support to protect the spinal cord and nerves, and they provide motion, and function to the skeleton.  Patients with AS often develop fused vertebral spines. 

Fused vertebral bones increase the chance of damaging the bones and place-increased stress on surrounding structures such as ligaments, tendons, and muscles.  A fused spine creates not only pain but loss of motion, and can become more brittle with mechanical stresses.  If vertebrae become fractured and dislodge, there is an increased risk of damage from impingement of surrounding spinal cord structures and nerves.  Damage to the spinal cord, roots and nerves cause symptoms such as changes in sensation, strength and movement below the level of injury.  For example, decreased leg strength with numbness and tingling in a patient complaining of back pain may be a sign of spinal nerve compromise.  If symptoms such as these occur, immediate medical attention should be sought.  Other symptoms that should prompt emergent medical attention include saddle area numbness and/or new changes in bowel and bladder habits (e.g. constipation, loss of continence).