Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease that affects the joints between the vertebrae of the spine, and the joints between the spine and the pelvis. It eventually causes the affected vertebrae to fuse or grow together.

The first sign of the disease is intermittent hip and/or lower-back pain that is worse at night, in the morning, or after inactivity. Back pain begins in the sacroiliac joint (between the pelvis and the spine) and may progress to include the lumbar (lower back) area and the chest area of the spine. About 0.21% of Americans over age 15 are affected.

The pain may be eased by bending over. This is due to limited expansion of the chest which occurs because of the involvement of the joints between the ribs.

When the Disease Strikes

  • Between the ages of 20 and 40
  • Affects more males than females
  • If a family has a history of AS in the male gender

With progressive disease, deterioration of bone and cartilage can lead to fusion in the spine or peripheral joints, affecting mobility. It can be extremely painful and crippling. The heart, the lungs, and the eyes may also become affected.

Symptoms

  • Low-back pain that is worse at night, in the morning, or after inactivity
  • Stiffness and limited motion in the low back
  • Hip pain and stiffness
  • Limited expansion of the chest
  • Limited range of motion, especially involving spine and hips
  • Joint pain and joint swelling in the shoulders, knees, and ankles
  • Neck pain
  • Heel pain
  • Chronic stooping to relieve symptoms
  • Fatigue
  • Low grade fever
  • Loss of appetite
  • Weight loss
  • Eye inflammation
  • Signs and tests

Oddly symptoms may get worse, disappear, or stop at any stage.

A physical examination and characteristic symptoms are indicative of limited spine motion or chest expansion.

Tests may include:

  • HLA-B27 antigen test is positive.
  • A spine X-ray or pelvic X-ray shows characteristic findings.
  • ESR may or may not be elevated.
  • CBC may show mild anemia.

Medications

  • Nonsteroidal anti-inflammatory medications (NSAIDs)
  • Corticosteroid therapy or medications
  • Cytotoxic drugs (drugs that block cell growth)
  • Drugs called TNF-inhibitors

Surgery

Surgery is done if pain or joint damage is severe.

Exercise/Relief

Exercise can help improve posture and breathing.

Lying flat on the back at night can help maintain normal posture.

Prognosis

The course of ankylosing spondylitis is unpredictable. Remissions and relapses may occur at any stage. Most people are able to function unless the hips are severely involved.

Complications

  • Heart valve disease, typically aortic valve stenosis
  • Aortitis
  • Eye inflammation (uveitis)
  • Pulmonary fibrosis

When to Contact Your Doctor

If you have symptoms of ankylosing spondylitis or if you have ankylosing spondylitis and new symptoms develop during treatment.

Prevention and Treatment

There is no known prevention. Knowing the risk factors helps with early detection and treatment.