Ankylosing spondylitis

What is Ankylosing spondylitis?

Ankylosing spondylitis is a chronic inflammation of the spine, which is seen where vertebrae join each other. This inflammatory disease also affects the hips, shoulders, and ribs. It usually begins in the late teens or early twenties. The disease is diagnosed more frequently in males than in females. In most cases, ankylosing spondylitis is a mild condition that goes undiagnosed for decades. There can be a hereditary tendency to develop the disease. The cause is unknown, but is suspected to be an autoimmune disease.

How is it diagnosed?

• History: Chronic low back pain and stiffness are typically the first symptoms of ankylosing spondylitis. Pain is characteristically worse with rest and improves with activity. Symptoms develop gradually, so that individuals often cannot report when it began. There is not a history of injury. There may be a family history of this disease or some "arthritis of the spine."
• Physical exam: The earliest physical finding in ankylosing spondylitis is usually tenderness over the sacroiliac joints. As the disease progresses, the spine becomes more rigid, and bending in any direction becomes more restricted. When the disease has advanced to the thoracic spine, chest expansion becomes restricted also. The individual's posture becomes "stooped." In later stages of the disease, pain and stiffness in neck (cervical) joints and muscles occur, so that the neck cannot be fully extended and eventually the neck becomes fixed in a bent-forward (flexed) position.
• Tests: Routine lab tests are normal. The disease may be suspected by the presence of an antigen (HLA-B27) in the blood. Early x-ray changes are sacroiliac joint rarefaction (localized osteoporosis) and "squaring" of the vertebral bodies. A CT scan can detect sacroiliac changes early in the disease. Later, sclerosis of these joints is evident on plain x-rays and osteophytes that bride from (fuse) one vertebral body to another is visible.

How is it treated?

Anti-inflammatory drugs (DMARDs) are used to relieve the chronic pain and stiffness. If there is no response to this type of treatment, drugs to suppress the immune response can be added. Physical therapy and stretching exercises are used to offset the reduced flexibility of the disease. Pool exercise, deep breathing exercise, and thoracic extension exercises are helpful. Surgery might be needed to correct severe spine disease or stooped-over posture or to replace damaged hip joints.

Medications

What might complicate it?

Fractures of the spine can occur without any injury. Heart disease occurs in a small minority of individuals with long standing, severe disease. Inflammation of the eye (anterior uveitis) is associated in as many as 25% of cases. Formation of fibrous tissue in the lungs (pulmonary fibrosis) may occur, usually long after the onset of skeletal symptoms. Pneumonia is more common than in the general population.

Predicted outcome

The majority of individuals with ankylosing spondylitis are able to live normal lives. In recent studies, only ten to twenty percent become significantly disabled over a period of 20 to 40 years. A pattern of disease progression usually emerges after the first ten years.

Alternatives

Other disorders that have common presenting features are Reiter's syndrome, psoriatic arthritis, and the arthritis associated with inflammatory bowel disease. There are many other causes of spine pain that don't involve inflammation of the joints between vertebrae.

Rehabilitation

Physical therapy (heat packs, electrostimulation, deep breathing, back extension exercise), three times a week, for a period of four weeks.

Appropriate specialists

Rheumatologist, ophthalmologist, orthopedic surgeon, and physiatrist.

Last updated 27 May 2015