The cause of ankylosing spondilitis is unknown, but genetic factors seem to play a role. The disease starts with intermittent hip and/or lower-back pain that is worse at night, in the morning, or after inactivity.

Back pain begins in the sacroiliac joint (between the pelvis and the spine) and may progress to include the lumbosacral spine and the thoracic spine (chest portion of the spine).

Pain may be eased by assuming a bent posture. Limited expansion of the chest occurs because of the involvement of the joints between the ribs. The symptoms may worsen, go into remission, or stop at any stage.

With progressive disease, deterioration of bone and cartilage can lead to fusion in the spine or peripheral joints, affecting mobility. It can be extremely painful and crippling. The heart, the lungs, and the eyes may also become affected.

The disease most frequently begins between age 20 and 40, but may begin before age 10. It affects more males than females. Risk factors include a family history of ankylosing spondylitis and male gender. About 0.21% of Americans over age 15 are affected.

• low-back pain that is worse at night, in the morning, or after inactivity
• stiffness and limited motion in the low back
• hip pain and stiffness
• limited expansion of the chest
• limited range of motion, especially involving spine and hips
• joint pain and joint swelling in the shoulders, knees, and ankles
• neck pain
• heel pain
• chronic stooping to relieve symptoms
• fatigue
• fever, low grade
• loss of appetite
• weight loss
• eye inflammation

• HLA-B27 antigen test is positive.
• A spine X-ray or pelvis X-ray shows characteristic findings.
• ESR may or may not be elevated.
• CBC may show mild anemia.

The goal is to relieve the joint pain and to prevent, delay, or correct deformities.

MEDICATIONS

Nonsteroidal anti-inflammatory medications (NSAIDs) such as aspirin are used to reduce inflammation and pain associated with the condition. They allow patients to exercise, which improves posture and breathing.

DO NOT give aspirin or other NSAIDs to children unless advised to do so by the health care provider!

Corticosteroid therapy or medications to suppress the immune system may be prescribed to control various symptoms. Some health care professionals use cytotoxic drugs (drugs that block cell growth) in people who do not respond well to corticosteroids or who are dependent on high doses of corticosteroids.

Drugs called TNF-inhibitors have been shown to improve the symptoms of ankylosing spondylitis.

SURGERY

Surgery is done if pain or joint damage is severe.

LIFESTYLE CHANGES

Exercises can help improve posture and breathing. Lying flat on the back at night can help maintain normal posture. Use devices to help with activities of daily living.

• heart valve disease, typically aortic valve stenosis
• aortitis
• eye inflammation (uveitis)
• pulmonary fibrosis