Ankylosing spondylitis is a type of arthritis which is primarily characterized by chronic inflammation of the joints and ligaments of the spine, causing pain and stiffness in the spine. In severe cases, bones in the spine may fuse (also referred to as ankylosis) resulting in a rigid and inflexible spine. Abnormal posture may be a consequence. Other joints may also be involved including hips, knees, ankles, neck, or shoulders. The disease may also have systemic effects (i.e. affecting various organs of the body).
The cause of ankylosing spondylitis is unknown but since the HLA-B27 gene is present in 90 percent of people with ankylosing spondylitis, there appears to be a genetic connection. However, it's important to know that not everyone who has the HLA-B27 gene develops ankylosing spondylitis. Other risk factors are involved.
Inflammation associated with ankylosing spondylitis commonly starts at the lower spine or sacroiliac joints. The earliest symptoms are often chronic pain and stiffness in the lower back region and hips. Typical ankylosing spondylitis pain in the back worsens following rest or inactivity.
As symptoms of pain and stiffness progress up the spine to the neck, possibly including the rib cage area, bones may fuse and normal movement is lost. If the rib cage is involved, abnormal chest expansion may cause breathing difficulties.
Complications may include:
Diagnosis of ankylosing spondylitis is based on symptoms (e.g. pain and stiffness), physical examination (e.g. check for tenderness and decreased range of motion), x-rays (e.g.abnormalities of the spine or sacroiliac joints) and blood tests (e.g. HLA-B27). Early symptoms of ankylosing spondylitis can cause confusion because they mimic other conditions. Patients are also checked for signs of other spondyloarthropathies (i.e. reactive arthritis, psoriatic arthritis, enteropathic arthritis). Enteropathic arthritis is a chronic type of inflammatory arthritis associated with inflammatory bowel disease.
Treatments for ankylosing spondylitis focus on reducing pain, stiffness, and inflammation. Preventing deformity, maintaining function and good posture are also goals of treatment.
Treatment options for ankylosing spondylitis are similar to rheumatoid arthritis.
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- DMARDs (e.g. methotrexate, sulfasalazine)
- Oral corticosteroids are used rarely
- TNF-blockers (e.g. Humira, Remicade, Enbrel)
Physical therapy and exercise routines are a significant part of any treatment plan for ankylosing spondylitis.
Ankylosing spondylitis primarily affects men. Two to three times more men than women develop the disease. Anyone can develop ankylosing spondylitis however. The age of disease onset is usually between 17 to 35 years old. The incidence of ankylosing spondylitis is 1 in 1,000 persons. Some researchers believe it is 1 in 200 persons.
- Ankylosing spondylitis is one in a group of conditions known as spondyloarthropathies.
- Only about 10 percent of ankylosing spondylitis patients do not have the HLA-B27 gene.
- Only about 10 percent of people who do have the HLA-B27 gene will develop ankylosing spondylitis.
- In women with ankylosing spondylitis, joints other than the spine are more frequently affected than in men.
- Ankylosing spondylitis rarely develops after 45 years of age.
- Ankylosing Spondylitis: Often a Delayed or Difficult Diagnosis
- Guide to Low Back Pain
- What is the Spine?
Sources:
1. "Ankylosing Spondylitis." Arthritis Foundation. 22 Feb 2007 <http://www.arthritis.org/conditions/DiseaseCenter/ankylosing_spondylitis.asp>
2. "Spondyloarthropathy." Cleveland Clinic. 22 Feb 2007 <http://www.clevelandclinic.org/health/health-info/docs/4100/4141.asp?index=13291>
3. "About Spondylitis." Spondylitis Association of America. 22 Feb 2007 <http://www.spondylitis.org/about/main.aspx?YYZ=NAV02>
