Ankylosing spondylitis is a variety of arthritis resulting in the extreme stiffness and fusing of the spine's vertebrae.
A similar phenomenon may afflict other joints of the body--though the term spondylitis would be somewhat inapplicable in those situations, the term is sometimes used anyway, as that which affects the vertebral column is one of the more common forms of the affliction.
Other potential effects of the disease can include disorders of the major organs and the development of cataracts in the eyes, though these complications are usually considered rare. Abnormal curvature of the spine may sometimes occur as a result of vertebral fusion.
Ankylosing spondylitis is not considered life-threatening in the least, but it can be painful and it can cause minor to moderate disability, depending upon the seriousness of the individual condition. It is significantly more likely to afflict males than females (by a margin of about three to one), and also much more likely to afflict Caucasians than African-Americans (by that same approximate margin, once again). About one percent of Americans are affected by AS, and about 6% of Americans have the marker gene that indicates a propensity toward the condition. The disease most commonly makes its onset after adolescence and before the onset of middle age, and occurs very gradually. Its symptoms may not always be obvious, save that those afflicted will probably realize they're affected by some form of arthritis after seeing a doctor for stiffness.
Treatment usually involves the administration of non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin, ibuprofen and acetaminophen, as well as stronger but similar medications. Exercise is indicated as potentially highly beneficial in improving flexibility and preventing escalation of the condition; immobility is contraindicated, as it encourages the growth of permanent bone tissue.
Hereditary factors seem to have some impact upon the likelihood of developing ankylosing spondylitis, as most people with AS share an unusual genetic marker. However, as not all people who have this marker develop AS (only approximately 20% do), some other hereditary factors or environmental triggers not altogether clear at this time must be involved as well. Studies are still underway to determine precisely what causes this condition in some but not in others, and focus on the abnormal way in which patients with the condition regrow bone tissue after the wear induced with inflammation. While normal subjects tend only to regrow what bone is worn away, give or take a portion, AS patients respond with an excessive level of growth that results in the eventual fusion of the joint in question.
