Experts don't know exactly how common ankylosing spondylitis is, because the condition is often not diagnosed. The prevalence (how common it is) differs among groups of people.
Ankylosing spondylitis is 2 to 3 times more common in men than in women. Among white Europeans and North Americans, 7 in 10,000 men and fewer than 2 in 10,000 women have ankylosing spondylitis.1 It is often found in certain ethnic groups, such as some Native American tribes, Inuits, and Siberian Chukotkas. It is much less common in people whose family is Japanese or African.2
The only clear risk factor for ankylosing spondylitis is having a close family member who has the condition. About 15% to 20% of people with ankylosing spondylitis have another family member who has it.2 Having a gene known as HLA-B27 and having frequent infections of the gastrointestinal system (stomach and other organs of digestion) may also increase your risk.2
References
Citations
Woolf AD, et al. (2007). Healthcare services for those with musculoskeletal conditions: A rheumatology service. Recommendations of the European Union of Medical Specialists Section of Rheumatology/European Board of Rheumatology 2006. Annals of the Rheumatic Diseases, 66(3): 293–301.
Davis JC Jr (2005). Ankylosing spondylitis. In WJ Koopman, LW Moreland, eds., Arthritis and Allied Conditions: A Textbook of Rheumatology, 15th ed., vol. 1, pp. 1319–1334. Philadelphia: Lippincott Williams and Wilkins.
Credits
| Author | Shannon Erstad, MBA/MPH |
| Editor | Kathleen M. Ariss, MS |
| Associate Editor | Tracy Landauer |
| Associate Editor | Pat Truman, MATC |
| Primary Medical Reviewer | E. Gregory Thompson, MD - Internal Medicine |
| Specialist Medical Reviewer | Stanford M. Shoor, MD - Rheumatology |
| Last Updated | May 18, 2007 |
