Ankylosing Spondylitis (AS)
What is it?
Arthritis is a complex family of musculoskeletal disorders consisting of more than 100 different diseases or conditions that destroy joints, bones, muscles, cartilage and other connective tissues, hampering or halting physical movement.Ankylosing spondylitis (AS) is a chronic inflammatory disease that primarily affects the sacroiliac joints (where the spine attaches to the pelvis), spine, and hip joints. Ankylosing is a term meaning stiff or rigid and spondylitis means inflammation of the spine.
Enthesitis (inflammation of the place where ligaments and muscles attach to bones) accounts for much of the pain and stiffness of AS. This inflammation eventually can lead to bony fusion of the joints (where the fibrous ligaments transform to bone, and the joint permanently grows together).
Other joints can also develop synovitis (inflammation of the lining of the joint), with lower limb joints more commonly involved than upper-limb joints.
AS is one of a family of arthritis-related diseases called the seronegative spondylarthropathies. Seronegative means people with the disease test negative for the antibody rheumatoid factor and spondylarthropathy means joint disease of the spine. Ankylosing spondylitis most often develops in young adult men and it lasts a lifetime.
What are the effects?
Pain in the low back and buttocks are usually the first symptoms of AS. In contrast to mechanical low back pain, low back pain and stiffness in AS patients are worse after a period of rest or on waking up in the morning and improve after exercise, a hot bath or a shower. Progressive stiffening of the spine is usual, with ankylosis (fusion of some or all spinal joints) occurring after some years of disease in many, but not all, patients. A majority of patients have mild or moderate disease with intermittent exacerbations and remissions and maintain some mobility and independence throughout life.
How is it diagnosed?
A diagnosis of ankylosing spondylitis (AS) is usually made by a rheumatologist and usually requires the following:
- X-ray evidence of sacroiliitis (inflammation of the sacroiliac joint, which is the joint where the spine attaches to the pelvis)
And one of the following three key signs:
- Low back pain and stiffness for more than 3 months, which improves with exercise, but is not relieved by rest
- Limitation of motion of the lumbar spine in both the bending to the side and to the front.
- Limitation of chest expansion relative to normal values corrected for age and sex
Early in the disease course, however, the X-ray evidence required by the criteria may not be present. Your doctor can make a diagnosis of AS based on your symptoms and start treatment without the X-ray evidence. If your symptoms lead your doctor to believe that you have AS, he or she may run a blood test for the presence of the HLA-B27 genetic marker, the presence of which will enhance the diagnosis.
What are the treatment options?
Although no medication or therapy can prevent ankylosing spondylitis (AS) from progressing, a treatment plan of medication and exercise can help you maintain a normal upright posture and spinal mobility, minimize the impact of hip and other joint manifestations, and reduce pain and stiffness.
A full treatment plan may include the following:
- Work and recreation adjustments:
- Medications: There are several drugs that may be used including:
- Nonsteroidal anti-inflammatory drugs
- Corticosteroid injections
- Oral corticosteroids
- Tumor necrosis factor inhibitors
What resources are available?
The Arthritis Foundation leads the way in helping people with arthritis live better today and create better tomorrows through new treatments, better access and, ultimately, cures. We do this by:
- Funding life-changing research that has restored mobility in patients for more than six decades
- Fighting for health care policies that improve the lives of the millions of Americans with arthritis
- Partnering with families to provide empowering programs and information
If you are diagnosed with ankylosing spondylitis, some Arthritis Foundation resources that may help you better manage and live with your disease are:
- Learn more about arthritis treatments.
- Discover ways to make living with arthritis easier.
- Understand the causes of pain and the best ways to manage it.
- Discover what is happening with arthritis research.
- Help researchers find more effective treatments.
- Tell Congress more needs to be done for people with arthritis.