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. The 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 a mild and slowly progressive arthritis, with pathology similar to RA..