Ankylosing spondylitis

Ankylosing Spondylitis (AS) is a chronic, progressive inflammatory arthritis primarily affecting spine and sacroiliac joints, causing eventual fusion of the spine. It is characterised as a spondyloarthropathy (SpA).


In the USA, the prevalence is 0.25%, but as it is a chronic condition, the number of new cases (incidence) is fairly low. The sex ratio is 3:1 for men:women.


AS is a systemic rheumatic disease, and about 90% of the patients are HLA-B27 positive. HLA-DR and IL1ra are also implicated in Ankylosing Spondylitis.

Signs and symptoms

The typical patient is a young man of 15-30 years old (although women are also affected) with pain and stiffness in the spine. It is also associated with iridocyclitis (anterior uveitis), ulcerative colitis, psoriasis and Reiter's disease, through HLA-B27 (see below).
Organs affected by AS, other than the axial spine, are the hips, heart, heels, and other areas (peripheral).


The diagnosis is by X-ray studies of the spine, which show characteristic spinal changes and sacroiliitis. A normal X-ray does not exclude the disease.
HLA-B27 is occasionally used, but does not distinguish AS from other diseases and is therefore not of real diagnostic value.


Physical therapy and exercise, along with medication, are at the heart of therapy for ankylosating spondylitis.

Medications used are:

  • NSAIDs (anti-inflammatory and pain-reducing)

  • Steroids

  • DMARDs (immunosuppressants)


AS can range from mild to progressively debilitating, and from medically controlled to refractive.

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