Two professors of medicine offer five key questions to consider when evaluating patients for ankylosing spondylitis (AS). Making an early diagnosis is important in developing a plan of care that will control symptoms. But making the diagnosis early can be a challenge because hallmark signs of AS seen on X-rays don’t show up for seven to 10 years. These five questions can help doctors stay alert to the possibility of AS:
Ankylosing spondylitis (AS) is a chronic, painful, inflammatory arthritis that mainly affects the spine and sacroiliac joints (SIJs). It can eventually cause the sacroiliac joints and spine to fuse.
Ankylosing spondylitis is one of several different arthritides or arthropathies. These terms refer to joints that are affected by arthritis. When a rheumatological disease affects the spine, the resulting condition is called a spondyloarthropathy. The term is made up of Greek words: spondylo means vertebra, arthro means joint and pathos means disease.
In answer to the five questions, the authors offer some valuable information intended for primary care physicians who will be making the diagnosis. Since there isn’t one diagnostic test that confirms the presence of AS, the physician must take several steps in making the diagnosis.
First, anyone with back pain lasting more than three months who is less than 40 years old and who complains of morning stiffness that gets better with movement could be experiencing some form of inflammatory back pain (IBP).
These patient characteristics are not (by themselves) enough to diagnose AS. Family and personal history is important, along with assessment of all signs and symptoms affecting any part of the body. During the early phase of AS, additional testing may be needed. This could include lab and imaging studies.
One blood test for the presence of the HLA-B27 gene is helpful but not conclusive. Some people who have AS don’t have this gene. But, in general, people who have the HLA-B27 gene have a higher risk of developing AS than those who don’t have this gene. The presence of back pain in someone with the gene is a yellow (warning) flag. In those cases, an MRI scan of the sacroiliac joints is needed. The MRI can show early changes that don’t appear on X-rays.
Once the diagnosis has been made, then other family members should be informed and evaluated. Men are 10 times more likely to be affected compared to women. When AS affects women (mother, sisters, children) of the patient with AS, they are more likely to have changes in the thoracic spine and costovertebral joints (where the ribs attach to the vertebrae).
What’s the best treatment for this problem? Antiinflammatory drugs and physical therapy are started right away. If these two treatment modalities don’t improve the pain and stiffness, then other treatment options are considered. This may include biologic agents such as tumor necrosis factor – alpha inhibitor. These biologic agents help slow down progression of the disease.
Tumor necrosis factor inhibitors can help even when the spine has become fused. Biologic agents may help even in advanced cases. There is always some amount of inflammation in the joints (even after fusion). The authors provide guidelines for the use of these inhibitors. For example, they are first considered for patients who do not get symptom relief when two or more nonsteroidal antiinflammatory drugs have been taken for at least three months. These biologic agents can cause infection, so patients must be screened for tuberculosis.
The authors conclude that controlling joint and spine pain and stiffness that comes with AS is possible, especially when the diagnosis is made early and treatment started right away. With early treatment, it may be possible to prevent spinal deformities and fusion. MRIs can be used to monitor inflammation and disease progression.