Between 0.1% and 0.8% of people are affected. The disease is most common in Northern European countries, and seen least in people of Afro-Caribbean descent. Although the ratio of male to female disease is reportedly 3:1, many rheumatologists believe the number of women with AS is underdiagnosed, as most women tend to experience milder cases of the disease. The majority of people with AS, including 95 percent of people of European descent with the disease, express the HLA-B27 antigen and high levels of immunoglobulin A (IgA) in the blood.
Ankylosing spondylitis
Plantar fasciitis
Axial spondyloarthritis
Oligoarthritis
Osteoarthritis
Spondyloarthropathy
Enteropathic arthropathy
Spondylolysis