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Ankylosing Spondylitis


Ankylosing spondylitis is part of a larger symptom complex of so called “spondyloarthropathies” that affect the spine and the insertion of tendons and ligaments.

They are distinct from rheumatoid arthritis, and they include apart from ankylosing spondylitis also Reiter’s syndrome, psoriatic arthritis, and enteropathic arthritis (ulcerative colitis, Crohn’s disease).

There is clustering of cases in certain families who have a genetically changed cell surface antigen, called “HLA-B27” and “HLA-B7” (Ref. 2) that is found on white blood cells in patients with ankylosing spondylitis. Also, males are about 2 1/2 times more frequently affected with this than females. Chronic back pain is more common in males than in females with ankylosing spondylitis (Ref. 1, chapter 12). It begins often in the age group of 20 to 40.

Here is the frequency of some of the various types of spondyloarthropathies in the population (modified from Ref. 1, p.48).

 Ankylosing Spondylitis

Ankylosing Spondylitis

Frequency of cases of spondyloarthropathies

Name of disease:        No. of cases per 100,000 people:
Ankylosing spondylitis
Psoriatic arthritis
Reactive arthritis and Reiter’s syndrome
Ulcerative colitis (enteroarthropathy)
Crohns disease


1.The Merck Manual, 7th edition, by M. H. Beers et al., Whitehouse  Station, N.J., 1999. Chapter 51.

2. Goldman: Cecil Textbook of Medicine, 21st ed.(©2000)W.B.Saunders

3. ABC of rheumatology, second edition, edited by Michael L. Snaith,M.D., BMJ Books, 1999.

4. Ferri: Ferri’s Clinical Advisor: Instant Diagnosis and Treatment, 2004 ed., Copyright © 2004 Mosby, Inc.

5. Rakel: Conn’s Current Therapy 2004, 56th ed., Copyright © 2004 Elsevier

Last modified: October 14, 2014

This outline is only a teaching aid to patients and should stimulate you to ask the right questions when seeing your doctor. However, the responsibility of treatment stays in the hands of your doctor and you.