Seronegative Spondyloarthropathies

SERONEGATIVE SPONDYLOARTHROPATHIES

Seronegative spondyloarthropathies are a group of disorders characterized by the following:

•  Rheumatoid factor seronegativity
•  Involvement of the sacroiliac joints
•  Association with HLA-B27

Ankylosing spondylitis occurs predominantly in young men with HLA-B27 (90% of cases); usually involves the sacroiliac joints and spine, and may be associated with inflammatory bowel disease.

Reactive arthritis is characterized by a classic triad of conjunctivitis, urethritis, and arthritis. Arthritis affects the ankles and knees. It affects males more than females, with onset age 20s–30s. Onset often follows a venereal disease or bacillary dysentery.

Enteropathic arthritis occurs in 10–20% of patients with inflammatory bowel disease.

Psoriatic arthritis affects 5–10% of patients with psoriasis; is often mild and slowly progressive arthritis, with pathology similar to RA.