Spondyloarthropathy


Spondyloarthropathy or spondyloarthrosis refers to any joint disease of the vertebral column. As such, it is a class or category of diseases rather than a single, specific entity. It differs from spondylopathy, which is a disease of the vertebra itself. However, many conditions involve both spondylopathy and spondyloarthropathy.
Spondyloarthropathy with inflammation is called axial spondyloarthritis. In the broadest sense, the term spondyloarthropathy includes joint involvement of vertebral column from any type of joint disease, including rheumatoid arthritis and osteoarthritis, but the term is often used for a specific group of disorders with certain common features, the group often being termed specifically seronegative spondylarthropathies. They have an increased incidence of HLA-B27, as well as negative rheumatoid factor and ANA. Enthesopathy is also sometimes present in association with seronegative.
Non-vertebral signs and symptoms of degenerative or other not-directly-infected inflammation, in the manner of spondyloarthropathies, include asymmetric peripheral arthritis, arthritis of the toe interphalangeal joints, sausage digits, Achilles tendinitis, plantar fasciitis, costochondritis, iritis, and mucocutaneous lesions. However, lower back pain is the most common clinical presentation of the causes of spondyloarthropoathies; this back pain is unique because it decreases with activity.

Seronegative spondyloarthropathy

Seronegative spondyloarthropathy is a group of diseases involving the axial skeleton and having a negative serostatus.
"Seronegative" refers to the fact that these diseases are negative for rheumatoid factor, indicating a different pathophysiological mechanism of disease than what is commonly seen in rheumatoid arthritis.

Conditions

The following conditions are typically included within the group of seronegative spondylarthropathies:
ConditionPercent of people with the
condition who are HLA-B27 positive
Axial spondyloarthritis
  • Caucasians: 92%
  • African-Americans: 50%
Reactive arthritis 60–80%
Enteropathic arthropathy or spondylitis associated withinflammatory bowel disease 60%
Psoriatic arthritis40–50%
Isolated acute anterior uveitis50%
Juvenile idiopathic arthritis
Undifferentiated spondyloarthropathy 20–25%

Some sources also include Behcet's disease and Whipple's disease.

Common characteristics

These diseases have the following conditions in common:
Assessment of Spondylarthritis International Society is used for classification of axial spondyloarthritis. It is of two broad types:
  1. Sacroiliitis on imaging plus 1 SpA feature, or
  2. HLA-B27 plus 2 other SpA features
Sacroiliitis on imaging:
SpA features:
Worldwide prevalence of spondyloarthropathy is approximately 1.9%.