1. What is Ankylosing spondylitis?
Ankylosing spondylitis belongs to a group of disorders called seronegative spondyloarthropathies. Seronegative means an individual has tested negative for an autoantibody called rheumatoid factor. The spondyloarthropathies are a family of similar diseases that usually cause joint and spine inflammation. Other well-established syndromes in this group include psoriatic arthritis, the arthritis of inflammatory bowel disease, chronic reactive arthritis, and enthesitis-related idiopathic juvenile arthritis.
Although these disorders have similarities, they also have features that distinguish them from one another. The hallmark of ankylosing spondylitis is “sacroiliitis,” or inflammation of the sacroiliac (SI) joints, where the spine joins the pelvis.
In some people, ankylosing spondylitis can affect joints outside of the spine, like the shoulders, ribs, hips, knees, and feet. It can also affect entheses, which are sites where the tendons and ligaments attach to the bones. It is possible that it can affect other organs, such as the eyes, bowel, and—more rarely—the heart and lungs.
Although many people with ankylosing spondylitis have mild episodes of back pain that come and go, others have severe, ongoing pain accompanied by loss of flexibility of the spine. In the most severe cases, long-term inflammation leads to calcification that causes two or more bones of the spine to fuse. Fusion can also stiffen the rib cage, resulting in restricted lung capacity and function.
2. Who Has Ankylosing Spondylitis?
3. What Causes Ankylosing Spondylitis?
Scientists supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) recently discovered two additional genes—ERAP1 (previously known as ARTS1) and IL23R—that, along with HLAB27, may represent a large portion of the genetic risk for ankylosing spondylitis. Factors such as infections or normal bacteria that live in the intestines may trigger the disease in people who are genetically susceptible.
4. How Is Ankylosing Spondylitis Diagnosed?
Medical History
The medical history involves answering questions, such as the following:
- How long have you had pain?
- Where specifically is the pain in your back or neck? Are other joints affected?
- Is back pain better with exercise and worse after inactivity, such as when you first get up in the morning?
- Do you have other problems, such as eye problems or fatigue?
- Does anyone in your family have back problems or arthritis?
- Have you recently suffered from a gastrointestinal illness?
- Do you have any skin rashes such as psoriasis?
From your answers to these questions, your doctor can begin to get an idea of the diagnosis.
Physical Exam
During the physical exam, the doctor will look for signs and symptoms that are consistent with ankylosing spondylitis. These include pain along the spine and/or in the pelvis, sacroiliac joints, heels, and chest. Your doctor may ask you to move and bend in different directions to check the flexibility of your spine and to breathe deeply to check for any problems with chest expansion, which could be caused by inflammation in the joints where the ribs attach to the spine.
Radiologic Test
X ray and magnetic resonance imaging (MRI) may be used in making or confirming a diagnosis of ankylosing spondylitis, but these tests have limitations. X rays may show changes in the spine and sacroiliac joints that indicate ankylosing spondylitis; however, it may take years of inflammation to cause damage that is visible on x rays. MRI may allow for earlier diagnosis, because it can show damage to soft tissues and bone before it can be seen on an x ray. However, MRI is very expensive. Both tests may also be used to monitor the progression of ankylosing spondylitis.
Lab Tests
The main blood test for ankylosing spondylitis is one to check for the HLA-B27 gene, which is present in more than 95 percent of Caucasians with ankylosing spondylitis. However, this test also has limitations. The gene is found in much lower percentages of African Americans with ankylosing spondylitis and in ankylosing spondylitis patients from some Mediterranean countries. Also, the gene is found in many people who do not have ankylosing spondylitis, and will never get it. About 8 percent of Americans have the gene, but only a small percentage of those will have ankylosing spondylitis. Still, when the gene is found in people who have symptoms of ankylosing spondylitis and/or x-ray evidence of ankylosing spondylitis, this finding helps support the ankylosing spondylitis diagnosis.
5. What Type of Doctor Diagnoses and Treats Ankylosing Spondylitis?
- An ophthalmologist, who treats eye disease.
- A gastroenterologist, who treats bowel disease.
- A physiatrist, a medical doctor who specializes in physical medicine and rehabilitation.
- A physical therapist or rehabilitation specialist, who supervises stretching and exercise regimens.
Often, it is helpful to the doctors and the patient for one doctor to manage the complete treatment plan.
6. Can Ankylosing Spondylitis Be Cured?
7. Will Diet and Exercise Help?
Although there is no specific diet for people with ankylosing spondylitis, maintaining a healthy weight is important for reducing stress on painful joints. In people with rheumatoid arthritis, another inflammatory joint disease, a diet high in omega-3 fatty acids (found in coldwater fish, flax seeds, and walnuts) has been shown to help in reducing joint inflammation. Although the usefulness of omega-3 fatty acids is not as well studied in people with ankylosing spondylitis, there is some evidence that omega-3 supplements could reduce disease activity in people with ankylosing spondylitis.
Exercise and stretching, when done carefully and increased gradually, may help painful, stiff joints.
Strengthening exercises, performed with weights or done by tightening muscles without moving the joints, build the muscles around painful joints to better support them. Exercises that don’t require joint movement can be done even when your joints are painful and inflamed.
Range-of-motion exercises improve movement and flexibility and reduce stiffness in the affected joint. If the spine is painful and/or inflamed, exercises to stretch and extend the back can be helpful in preventing long-term disability.
Many people with ankylosing spondylitis find it helpful to exercise in water.
Before beginning an exercise program, it’s important to speak with a health professional who can recommend appropriate exercises.
8. What is the Prognosis for People with Ankylosing Spondylitis?
The course of ankylosing spondylitis varies from person to person. Some people will have only mild episodes of back pain that come and go, while others will have chronic severe back pain. In almost all cases, the condition is characterized by acute, painful episodes and remissions, or periods of time where the pain lessens.In the sacroiliac joints and spine, inflammation can cause pain and stiffness. Over time, bony outgrowths called syndesmophytes can develop that cause the vertebrae to grow together, or fuse. Fusion can also stiffen the rib cage, resulting in restricted lung capacity and restricted lung function.
A number of factors are associated with an ankylosing spondylitis prognosis. One study found that among people who had ankylosing spondylitis for at least 20 years, those who had physically demanding jobs, other health problems, or smoked had greater functional limitations from their disease. People with higher levels of education and a history of ankylosing spondylitis in the family tended to have less severe limitations from their disease.
A recent study supported by the NIAMS found that the likelihood of having severe joint damage increased with age at disease onset, and that men were twice as likely as women to be in that group. The study also found that current smokers were more than four times as likely to have severe damage as nonsmokers, and that having a genetic marker called DRB1*0801 seemed to protect against severe spine damage.