Ankylosing spondylitis (AS) is a spondyloarthropathy characterized by inflammatory disease of the back. Patients with AS typically complain of stiffness that is worst in the morning (or on arising) and improves with activity. The most specific, although not the most sensitive, symptom is the need to get up at night to relieve the pain. Pulmonary findings in patients with AS are unique among the autoimmune diseases. Instead of the usual basilar prominence of disease seen in such diseases as rheumatoid arthritis, chest radiography may show apical fibrosis, leading to confusion with tuberculosis. HLA-B27 is positive in approximately 90% of patients with definite AS, but the risk for AS in persons who are HLA-B27positive is very small. The test neither confirms nor eliminates the diagnosis of AS and, therefore, should not be ordered. Patients are usually rheumatoid factornegative. The presence of recurrent sciatica actually decreases the possibility of back pain being caused by AS.
- Prominent morning back stiffness.
Click here to return to the questions
Seminars in Medical Practice
Hospital Physician Board Review Manuals
Copyright © 2009, Turner White Communications
Updated 1/04/08 kkj