Ankylosing spondylitis

In ankylosing spondylitis, persistent joint inflammation affects the sacroiliac jonts at the back of the pelvis and the vertebrae in particular. If the spine is severly diseased, new bone grows between the vertebrae, which eventually fuse together.

This form of arthritis is four times more common in men than in women. A variant of ankylosing spondylitis is associtated, in some cases, with the persistent skin disorder psoriasis or with inflammatory bowel disease, such as Crohn’s disease.

What are the cause?

The cause of ankylosing spondylitis is unknown, but about 9 in 10 affected people have a particular antigen (a substance that is capable of stimulating an immune response in the body) called HLA-B27 on the surface of most cells. This antigen is inherited, which helps to explain why ankylosing spondylitis runs in some families. Most people with HLA-B27 do not develop the condition, and a bacterial infection is thought to trigger ankylosing spondylitis in those who are predisposed.

What are the symptoms?


The symptoms of ankylosing spondylitis usually appear in late adolescence or early adulthood and develop gradually over a period of months or even years. Men are usually more severely affected. The main symtpoms include:

- Lower back pain, which may spread down into the buttocks and thighs.
- Lower back stiffness that may be worse in the morning and improves with exercise.
- Pain in other joints, such as the hips, kness and shoulders.
- Pain and tenderness in the heels.
- Tiredness, weight loss, and mild fever.

If left untreated, ankylosing spondylitis can distort the spine, resulting in a stooped posture. If the joints between the spine and the ribs are affected, expansion of the chest becomes restricted. In some people, ankylosing spondylitis causes inflammation or damage to tissues in areas other than the joints, such as the eyes.

How is it diagnosed?

Your doctor may suspect that you have ankylosing spondylitis from the pattern of your symptoms. He or she will perform a physical examination and may arrange for an X-ray to look for evidence of fusion in the joints of the pelvis and the spine. Your doctor may also arrange for you to have blood tests to measure the level of inflammation and look for the HLA-B27 antigen.

What is the treatment?

Treatment if ankylosing pondylitis is aimed at relieving the symptoms and preventing the development of spinal deformity. Your doctor may prescribe a nonsteroidal antififlammatory drug to control pain and inflammation. He or she mau also refer you for physiotherapy, which may include breathing exercise and daily exercises to help to improve your posture, strengthen the back muscles, and prevent deformities of the spine. You may also benefit from regular physical activity, such as swimming, which may help to relieve pain an stiffness. If a joint such as a hip is affected, you may eventually need to have it replaced surgically.

If your mobility is severely reduced, you may need occupational therapy. The therapist may suggest that you use specially designed equipment and furniture to make your life easier.

What is the prognosis?

Although the condition is not curable, most people with ankylosing spondylitis are only mildly affected, causing minium disruption of their everyday lives. In many cases, early treatment and regular exercise help to relieve pain and stiffness of the back and prevent deformity of the spine. However, about 1 in 20 people who develop ankylosing spondylitis may eventually become disabled and have difficulty in carrying out many routine activities. If disability is due to an affected joint, a replacement may be carried out.