|Spondylitis is an inflammation of the facet joints between the vertebrae. It may be either infectious or noninfectious in origin and is a feature of several conditions described as spondyloarthropathies, including ankylosing spondylitis, psoriatic arthritis, reactive arthritis, and arthritis secondary to inflammatory bowel disease (i.e., Crohn’s disease, ulcerative colitis). In addition to inflammation of vertebral joints, these diseases involve some degree of arthropathy, presenting symptoms of arthritis such as pain, swelling, and stiffness of peripheral joints. Most individuals who have these conditions test positive for the human leukocyte antigen HLA-B27, suggesting a genetic origin. This group of spondyloarthropathies are also thought to be autoimmune diseases, but they are seronegative for rheumatoid factor (RF), which is diagnostic for autoimmune rheumatoid arthritis, the most common form of inflammatory arthritis.|
Spondylitis resulting from an immune response to infection in another part of the body, as in Reiter’s syndrome, should not be confused with primary infection of bone in the spine (osteomyelitis) or infection of a spinal disc (discitis).
Ankylosing spondylitis is a specific type of spondylitis, characterized by inflammation of the vertebral joints and the joints between the spine and pelvis (sacroiliac joints). Fixed deformity of the spine in the sagittal plane may occur.
Psoriatic arthritis occurs in some individuals with psoriasis, a chronic skin condition. About 1 in 20 individuals with psoriasis will develop symptoms of arthritis along with the skin condition. In general, individuals who have psoriasis have a higher prevalence of arthritis than the general population. The cause of psoriatic arthritis is not known, but genetic factors may play a role.
Reiter's syndrome is an inflammatory complication of previous infection elsewhere in the body. Its symptoms include inflammation of the urethra (urethritis), inflammation of the eye (conjunctivitis), skin lesions, and reactive arthritis.
Undifferentiated spondylitis, not associated with an underlying spondyloarthropathy, is a term used by some physicians to describe back pain of unknown etiology associated with degenerative changes on imaging studies.
Risk: The risk of spondylitis increases in individuals with other inflammatory conditions such as psoriasis, Crohn’s disease, or ulcerative colitis. Spondylitis occurs in about 5% of patients with psoriatic arthritis and more often in males than females (Van der Linden). The male-to-female ratio for ankylosing spondylitis is 2:1 to 3:1. Risk is also increased in individuals seropositive for HLA-B27, indicative of a genetic predisposition for ankylosing spondylitis, psoriatic arthritis, inflammatory bowel disease, and Reiter's syndrome.
Ankylosing spondylitis usually presents between the ages of 20 to 40 and affects more males than females.
Reiter’s syndrome occurs most commonly in men younger than 40 years old.
Incidence and Prevalence: The exact incidence of spondylitis is not known because it is a feature of a group of diseases. In the US, 0.21% of individuals over the age of 15 are affected by ankylosing spondylitis (Clowse). The prevalence of ankylosing spondylitis in the US is estimated to be 197 individuals in 100,000, which closely parallels the frequency of HLA-B27 (Van der Linden). The incidence rate for Reiter's syndrome is 3.5 individuals per 100,000 in the US and correlates with the incidence rate of urethritis/cervicitis and infectious diarrhea (dysentery) (Scoggins).
Source: Medical Disability Advisor