What is ankylosing spondylitis?
Unlike ordinary back pain, ankylosing spondylitis (AS) is not caused by physical trauma to the spine. Rather, it’s a chronic condition caused by inflammation in the vertebrae (the bones of the spine). AS is a form of spinal arthritis.
The most common symptoms are intermittent flare-ups of spinal pain and stiffness. However, the disease can also affect other joints, as well as the eyes and the intestines. In advanced AS, abnormal bone growth in the vertebrae may cause joints to fuse. This can severely reduce mobility. People with AS may also experience vision problems, or inflammation in other joints, such as the knees and ankles.
What are the warning signs?
1: You have unexplained pain in the lower back.
Typical back pain often feels better after rest. AS is the opposite. Pain and stiffness are usually worse upon waking. While exercise may make ordinary back pain worse, AS symptoms may actually feel better after exercise.
Lower back pain for no apparent reason is not typical in young people. Teens and young adults who complain of stiffness or pain in the lower back or hips should be evaluated for AS by a doctor. Pain is often located in the sacroiliac joints, where the pelvis and spine meet.
2: You have a family history of AS.
People with certain genetic markers are susceptible to AS. But not all people who have the genes develop the disease, for reasons that remain unclear. If you have a relative with either AS, psoriatic arthritis, or arthritis related to inflammatory bowel disease, you may have inherited genes that put you at greater risk for AS.
3: You’re young, and you have unexplained pain in the heel(s), joints, or chest.
Instead of back pain, some AS patients first experience pain in the heel, or pain and stiffness in the joints of the wrists, ankles, or other joints. Some patient’s rib bones are affected, at the point where they meet the spine. This can cause tightness in the chest that makes it hard to breathe. Talk to your doctor if any of these conditions occur or persist.
Who is typically affected by AS?
AS is more likely to affect young men, but it can affect both males and females. Initial symptoms usually appear in the late teen to early adult years. AS can develop at any age, however. The tendency to develop the disease is inherited, but not everyone with these marker genes will develop the disease. It’s unclear why some people get AS and others don’t. A majority of Caucasian people with the disease carry a particular gene called HLA-B27, but not all people with the gene develop AS. Up to 30 genes have been identified that may play a role.
How is AS diagnosed?
There is no single test for AS. Diagnosis involves a detailed patient history and physical exam. Your doctor may also order imaging tests, such as computed tomography (CT), magnetic resonance imaging (MRI), or X-ray. Some experts believe MRI should be used to diagnose AS in the early stages of the disease, before it shows up on X-ray.
How are biologics for AS given?
Biologics must be delivered into tissue just under the skin or deep into muscle. They’re not available in pill or oral form. You receive them through injections or infusions.
The frequency of injections or infusions needed will vary depending on the particular biologic therapy. You may receive an infusion every few months. Or you may require multiple starter injections, and then follow-up injections throughout the year.
For example, the biologic Simponi requires three starter injections — two injections on the first day of treatment and one injection two weeks later. Afterward, you’ll give yourself one injection every four weeks. If you take Humira, on the other hand, you’ll give yourself one injection every other week after four starter doses.