Ankylosing Spondylitis (AS) is a chronic form of arthritis. It mostly affects the bones and joints at the base of the spine where it connects with the pelvis. These joints can become swollen and inflamed. Over time, the affected spinal bones may join together.
AS is the main member of a family of similar forms of arthritis called spondyloarthritis. Other members include psoriatic arthritis, arthritis of inflammatory bowel disease and reactive arthritis. The family of arthritis appears to be quite common and affects up to 1 in 100 people.
The cause of AS is unknown. Genes seem to play a role. Most people with AS have positive HLA-B27.
The disease often begins between ages 20 and 40, but it may begin before age 10. It affects more males than females.
Ankylosing Spondylitis Symptoms
AS starts with low back pain that comes and goes. Low back pain becomes present most of the time as the condition progresses.
- Pain and stiffness are worse at night, in the morning, or when you are less active. The discomfort may wake you from sleep.
- The pain often gets better with activity or exercise.
- Back pain may begin in the between the pelvis and spine (sacroiliac joints). Over time, it may involve all or part of the spine.
- Your lower spine may become less flexible. Over time, you may stand in a hunched forward position.
Other parts of your body that may be stiff and painful include:
- Swelling and pain in the joints of the shoulders, knees and ankles
- The joints between your ribs and breastbone, so that you cannot expand your chest fully
- Swelling and redness of the eye
Fatigue is also a common symptom.
Ankylosing spondylitis may occur with other conditions, such as:
- Ulcerative colitis or Crohn disease
- Recurring or chronic eye inflammation
Ankylosing Spondylitis Diagnosis
Tests may include:
- ESR (a measure of inflammation)
- HLA-B27 antigen (which detects the gene linked to ankylosing spondylitis)
- Rheumatoid factor (which should be negative)
- X-rays of the spine and pelvis
- MRI of the spine and pelvis
Ankylosing Spondylitis Treatment
Your health care provider may prescribe drugs such as NSAIDs to reduce swelling and pain.
You may also need stronger medicines to control pain and swelling, such as:
- Corticosteroid therapy (such as prednisone) used for short periods of time
- A TNF-inhibitor (such as etanercept, adalimumab, infliximab, certolizumab or golimumab)
Surgery may be done if pain or joint damage is severe.
Exercises can help improve posture and breathing. Lying flat on your back at night can help you keep a normal posture.