There is no specific test to diagnose ankylosing spondylitis, but imaging by X-ray and MRI may show evidence of inflammation of the sacroiliac joint between the sacrum (the triangular bone at the lowest part of the back) and the ilium (the bone felt on the upper part of the hip). Some symptoms may include:
Inflammatory back pain (gradual in onset, lasting over three months, with stiffness and pain that is worse in the morning and improved with movement)
Reduced mobility of the spine
Reduced ability to expand the chest
Your doctor may order a number of different blood tests that can suggest ankylosing spondylitis. For example, if you have the disorder, you are likely to have an increased erythrocyte sedimentation rate (the rate at which red blood cells settle out of your blood) and increased levels of C-reactive protein (a protein that is usually not in blood at high levels but may be elevated in cases of inflammation). These two tests are general indications of inflammation in your body.
You may also have anemia. To exclude other causes of inflammatory arthritis, tests for rheumatoid factor (an antibody common in cases of rheumatoid arthritis) and anti-nuclear antibodies (common in cases of lupus and other similar conditions) may be ordered, which are usually negative in ankylosing spondylitis. Approximately 95% of Caucasian people with ankylosing spondylitis are positive for the HLA-B27 marker.
What Are the Treatments for Ankylosing Spondylitis?
If you are diagnosed with ankylosing spondylitis, it is important to seek help from a physical therapist. Regular exercise and efforts to maintain mobility may make the difference between preserving your movement and independence and becoming debilitated.
Deep breathing exercises may help keep the chest cage flexible. Swimming is an excellent form of exercise for people with spondylitis, because it helps maintain proper extension of the spine. For smokers, it is advisable to quit due to the potential breathing problems associated with ankylosing spondylitis.
Good posture is important. Patients should choose chairs, tables, and other work surfaces that will help them avoid slumped or stooped postures. Patients are encouraged to sleep on a hard mattress with their back straight. Do not sleep on several pillows with your neck flexed forward. Lying face down with the arms extended is an exercise to help maintain an erect posture.