Ankylosing Spondylitis

  • Ankylosing spondylitis is a form of arthritis featuring chronic inflammation of the spine and the sacroiliac joints (sacroiliitis).
  • Ankylosing spondylitis belongs to a group of arthritis conditions that tend to cause chronic inflammation of the spine (spondyloarthropathies).
  • Ankylosing spondylitis affects males two to three times more commonly than females.
  • Ankylosing spondylitis is a cause of back pain in adolescents and young adults.
  • The tendency to develop ankylosing spondylitis is genetically inherited.
  • The HLA-B27 gene can be detected in the blood of most patients with ankylosing spondylitis.
  • Ankylosing spondylitis can also affect the eyes, heart, lungs, and, occasionally, the kidneys.
  • The optimal treatment of ankylosing spondylitis involves medications that reduce inflammation or suppress immunity, physical therapy, and exercise.

 

 

Ankylosing spondylitis is a form of chronic inflammation of the spine and the sacroiliac joints. The sacroiliac joints are located at the low back base. The sacrum (the bone directly above the tailbone) meets the iliac bones (bones on either side of the pelvis’s upper buttocks). Chronic inflammation in these areas causes pain and stiffness in and around the spine, including the neck, middle back, lower back, and buttocks. Over time, chronic inflammation of the spine (spondylitis) can lead to a complete cementing together (fusion) of the vertebrae, referred to as ankylosis. Ankylosis causes loss of mobility of the spine.

 

 

Ankylosing spondylitis is also a systemic disease, meaning it can affect tissues throughout the body, not just the spine. Accordingly, it can cause inflammation in and injury to other joints away from the spine manifest as arthritis and other organs, such as the eyes, heart, lungs, and kidneys. Ankylosing spondylitis shares many features with several other arthritis conditions, such as psoriatic arthritis, reactive arthritis (formerly called Reiter’s disease), and arthritis associated with Crohn’s disease ulcerative colitis. These arthritic conditions can cause infection and inflammation in the spine, other joints, eyes, skin, mouth, and various organs. Given their similarities and tendency to cause inflammation of the spine, these medical conditions are collectively referred to as “spondyloarthropathies.” Ankylosing spondylitis is considered one of the many rheumatic diseases because it can cause symptoms involving muscles and joints.

 

Ankylosing spondylitis is two to three times more common in men than in women. In women, joints away from the spine are more frequently affected than in men. Ankylosing spondylitis affects all age groups, including children. When it affects children, it is referred to as juvenile ankylosing spondylitis. The most common age of onset of symptoms is in the second and third decades of life. Ankylosing spondylitis is often abbreviated AS and has been referred to as Bechterew’s disease.

 

Signs of Ankylosing Spondylitis

The symptoms of ankylosing spondylitis are related to inflammation of the spine, joints, and other parts of the body. Fatigue is a common symptom associated with active inflammation. Inflammation of the spine causes pain and stiffness in the low back, upper buttock area, neck, and spine’s remainder. The onset of pain and stiffness is usually gradual. It progressively worsens with loss of range of motion noticeable over months. Occasionally, the beginning is rapid and intense (flare-up). Lumbar pain (low back pain) and buttock pain are common manifestations of active inflammation in the lumbar spine and sacroiliac joints. The symptoms of pain and stiffness are often worse in the morning or after prolonged periods of inactivity. Motion, heat, and a warm shower often reduces pain and stiffness in the morning. Because ankylosing spondylitis usually affects adolescents, the onset of low back pain is sometimes incorrectly attributed to athletic injuries in younger patients.

Those who have chronic, severe inflammation of the spine can develop a complete bony fusion of the spine (ankylosis). Once fused, the spine’s pain disappears, but the affected individual has a total loss of spine mobility. These fused spines are incredibly brittle and vulnerable to breakage (fracture) when involved in trauma, such as motor vehicle accidents. Sudden onset of pain and mobility in the spinal area of these patients can indicate bone breakage. The lower neck (cervical spine) is the most common area for such fractures.

Chronic spondylitis and ankylosis cause forward curvature of the upper torso (thoracic spine), which limits breathing capacity. Spondylitis can also affect the areas where ribs attach to the upper spine, further limiting lung capacity. Ankylosing spondylitis can cause inflammation and scarring of the lungs, causing coughing and shortness of breath, especially with exercise and infections. Therefore, breathing difficulty can be a severe complication of ankylosing spondylitis.

People with ankylosing spondylitis can also have arthritis in joints other than the spine. This feature occurs more commonly in women. Patients may notice pain, stiffness, heat, swelling, warmth, and or redness in joints such as the hips, knees, and ankles. Occasionally, the small joints of the toes can become inflamed or “sausage” shaped. Inflammation can occur in the cartilage around the breastbone (costochondritis) as well as in the tendons where the muscles attach to the bone (tendinitis) and in ligament attachments to bone (enthesitis). Some people with this disease develop Achilles tendinitis, causing pain and stiffness in the heel’s back, especially when pushing off with the foot while walking upstairs. Inflammation of the tissues of the bottom of the foot, plantar fasciitis, occurs more frequently in people with ankylosing spondylitis.

Other areas of the body affected by ankylosing spondylitis include the eyes, heart, and kidneys. Patients with ankylosing spondylitis can develop inflammation of the iris (iritis), the colored portion of the eye. Iritis is characterized by redness and pain in the eye, especially when looking at bright lights. Recurrent attacks of iritis can affect either eye. In addition to the iris, the ciliary body and choroid of the eye can become inflamed; this is referred to as uveitis. Iritis and uveitis can be serious complications of ankylosing spondylitis that can damage the eye and impair vision and require an eye specialist’s (ophthalmologist) urgent care. Special medical treatments for severe eye inflammation are discussed in the treatment section below. (It should be noted that iritis and inflammation of the spine can occur in other forms of arthritis such as reactive arthritis [formerly known as Reiter’s syndrome], psoriatic arthritis, and the arthritis of inflammatory bowel disease.)

A rare complication of ankylosing spondylitis involves scarring of the heart’s electrical system, causing an abnormally slow heart rate (referred to as heart block). A heart pacemaker may be necessary for these patients to maintain a reasonable heart rate and output. In others, the part of the aorta closest to the heart can become inflamed, resulting in leakage of the aortic valve. In this case, patients can develop shortness of breath, dizziness, and heart failure.

Advanced spondylitis can lead to deposits of protein material called amyloid into the kidneys and result in kidney failure. Progressive kidney disease can lead to chronic fatigue and nausea. It can require removing accumulated waste products in the blood by a filtering machine (dialysis).

Ankylosing Spondylitis Symptom

Lower back pain

Common causes of lower back pain include strain injury from athletics or overuse, disc herniation, kidney infection, a pinched nerve in the spine, and pregnancy. Less common causes of back pain include infection of the spine, ankylosing spondylitis with lumbosacral and sacroiliac joint disease, compression fracture of a spinal vertebra, disc ligament tear (annular tear), and spinal tumor or cancer in the bone of the spine.

Symptoms that can be associated with low back pain include:

  • dull ache,
  • numbness,
  • tingling,
  • sharp pain,
  • pulsating pain,
  • pain with movement of the spine,
  • pins and needles sensation,
  • muscle spasm,
  • tenderness,
  • sciatica with shooting pain down one or both lower extremities,
  • rash, and
  • loss of continence of bowel or bladder.

Causes of Ankylosing Spondylitis

The tendency to develop ankylosing spondylitis is believed to be genetically inherited. A majority (nearly 90%) of people with ankylosing spondylitis are born with a gene known as the HLA-B27 gene. Blood tests have been developed to detect the HLA-B27 gene marker. They have furthered our understanding of the relationship between HLA-B27 and ankylosing spondylitis. The HLA-B27 gene appears only to increase the tendency of developing ankylosing spondylitis, while some additional factor(s), perhaps environmental factors, are necessary for the disease to occur or become expressed. For example, while 7% of the United States population has the HLA-B27 gene, only 1% of the population has ankylosing disease spondylitis. In northern Scandinavia (Lapland), 1.8% of the population has ankylosing spondylitis, while 24% of the general population has the HLA-B27 gene. Even among individuals whose HLA-B27 blood test is positive, the risk of developing ankylosing spondylitis appears to be further related to heredity. In HLA-B27-positive individuals who have relatives with the disease, the risk of developing ankylosing spondylitis is 12% (six times greater than for those whose relatives do not have ankylosing spondylitis).

Other genes have been identified that are associated with ankylosing spondylitis, including ARTS1 and IL23R. These genes seem to play a role in influencing immune function. It is anticipated that by understanding the effects of each of these known genetic risk factors, medical researchers will make significant progress in discovering a cure for ankylosing spondylitis.

How inflammation occurs and persists in different organs and joints in ankylosing spondylitis is a subject of active health research. Each individual tends to have a unique pattern of presentation and activity of the illness. The initial inflammation may result from activation of the body’s immune system, perhaps by a primary bacterial infection or a combination of infectious microbes. Once activated, the body’s immune system becomes unable to turn itself off, even though the initial bacterial infection may have long subsided. Chronic tissue inflammation resulting from the continued activation of the body’s immune system in the absence of active infection is the hallmark of inflammatory autoimmune disease.

What tests do health care professionals use to diagnose ankylosing spondylitis?

Ankylosing spondylitis diagnosis is based on evaluating the patient’s symptoms, a physical examination, X-ray findings (radiographs), and blood tests. Stiffness, pain, and decreased range of motion of the spine are characteristic of ankylosing spondylitis’s inflammatory back pain. Symptoms include pain and morning stiffness of the spine and sacral areas with or without accompanying inflammation in other joints, tendons, and organs. Early signs of ankylosing spondylitis can be very deceptive, as stiffness and pain in the low back can be seen in many other conditions. It can be incredibly subtle in women, who tend to (though not always). Years of the disease can pass before the diagnosis of ankylosing spondylitis is even considered.

The examination can demonstrate signs of inflammation and a decreased range of motion of joints. This can be particularly apparent in the spine. The flexibility of the low back and or neck can be reduced. There may be tenderness of the sacroiliac joints of the upper buttocks. Chest expansion with full breathing can be limited because of the rigidity of the chest wall. Severely affected people can have a stooped posture. The doctor can evaluate inflammation of the eyes with an ophthalmoscope.

Further clues to the diagnosis are suggested by X-ray abnormalities of the spine and the presence of the genetic marker HLA-B27 identified by a blood test. Other blood tests may provide evidence of inflammation in the body. For example, a blood test called the sedimentation rate is a nonspecific marker for inflammation throughout the body. It is often elevated in inflammatory conditions such as ankylosing spondylitis. X-ray tests of the sacroiliac joints can demonstrate signs of inflammation and erosion of bone. X-rays of the spine can progressively show straightening, “squaring” of the vertebrae, and end-stage fusion of one vertebra to the next (ankylosis). Fusion up and down the spine can lead to a “bamboo spine” appearance on X-ray tests with complete mobility loss.

Urinalysis is often done to look for accompanying abnormalities of the kidney as well as to exclude kidney conditions that may produce back pain that mimics ankylosing spondylitis. Patients are also simultaneously evaluated for symptoms and signs of other related spondyloarthropathies, such as psoriasis, venereal disease, dysentery (reactive arthritis or Reiter’s disease), and inflammatory bowel disease (ulcerative colitis or Crohn’s disease).

Holistic Remedies for Ankylosing Spondylitis

Physical therapy for ankylosing spondylitis includes instructions and exercises to maintain proper posture. This includes deep breathing for lung expansion and stretching exercises to improve spine and joint mobility. Since ankylosis of the spine tends to cause forward curvature (kyphosis), patients are instructed to maintain erect posture as much as possible and to perform back-extension exercises. Patients are also advised to sleep on a firm mattress and avoid using a pillow to prevent spine curvature. Ankylosing spondylitis can involve the areas where the ribs attach to the upper spine and the vertebral joints, thus limiting breathing capacity. Patients are instructed to maximally expand their chest frequently throughout each day to minimize this limitation.

Physical therapists customize exercise programs for each individual. Swimming can often be a very beneficial form of exercise, as it avoids the spine’s jarring impact. Ankylosing spondylitis need not limit an individual’s involvement in athletics. People can participate in carefully chosen aerobic sports when their disease is inactive. Aerobic exercise is generally encouraged as it promotes full expansion of the breathing muscles and opens the lungs’ airways.

Cigarette smoking is strongly discouraged in people with ankylosing spondylitis. It can accelerate lung scarring and seriously aggravate breathing difficulties. Occasionally, those with severe lung disease related to ankylosing spondylitis may require oxygen supplementation and medications to improve breathing.

People with ankylosing spondylitis may need to modify their daily living activities and adjust features of the workplace. For example, workers can change chairs and desks for proper postures. Drivers can use wide rearview mirrors and prism glasses to compensate for the limited motion in the spine.

Treatment for Ankylosing Spondylitis

The treatment of ankylosing spondylitis typically involves using medications to reduce inflammation and or suppress immunity to stop disease progression, physical therapy, and exercise. Drugs decrease inflammation in the spine and other joints and organs. Physical therapy and exercise help improve posture, spine mobility, and lung capacity.

Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to decrease the spine and other joints’ stiffness.


In some people with ankylosing spondylitis, joints’ inflammation, excluding the spine (such as the hips, knees, or ankles), becomes the primary problem. Inflammation in these joints may not respond to NSAIDs alone. For these individuals, the addition of disease-modifying antirheumatic drugs (DMARDs) that suppress the body’s immune system is considered. These medications may bring about a long-term reduction of inflammation. An alternative to sulfasalazine that is somewhat more effective is methotrexate, administered orally, or by injection. Frequent blood tests are performed during methotrexate treatment because of its potential for toxicity to the liver, which can even lead to cirrhosis, and toxicity to bone marrow, which can lead to severe anemia.


Medical research has shown that for persistent ankylosing spondylitis with spinal involvement unresponsive to anti-inflammatory medications, both sulfasalazine and methotrexate are ineffective. Newer, effective medicines for spine disease attack a messenger protein of inflammation called tumor necrosis factor (TNF). These TNF-blocking medications effectively treat ankylosing spondylitis by stopping disease activity, decreasing inflammation, and improving spinal mobility.

If nonsteroidal anti-inflammatory drugs (NSAIDs) are not effective in a patient whose condition is dominated by spinal inflammation (and 50% do respond), then biologic medications that inhibit tumor necrosis factor (TNF inhibitors) are used. All TNF inhibitors, including Remicade, Enbrel, Humira, and Simponi, can help treat ankylosing spondylitis. The improvement that results in TNF inhibition is sustained during years of treatment. Suppose the TNF inhibitors are discontinued for whatever reason. In that case, relapse of the disease occurs in virtually all patients within a year. If the TNF inhibitor is then resumed, it is typically sufficient.

Oral or injectable corticosteroids (cortisone) are potent anti-inflammatory agents. They can effectively control spondylitis and other inflammations in the body. Unfortunately, corticosteroids can have serious side effects when used on a long-term basis. So they are typically used for short periods when possible. These side effects include cataracts, thinning of the skin and bones (osteoporosis), easy bruising, infections, diabetes, and destruction of large joints, such as the hips.

Inflammation and diseases in other organs are treated separately. For example, inflammation of the eyes (iritis or uveitis) may require cortisone eyedrops (Pred Forte) and high doses of cortisone by mouth. Additionally, atropine eyedrops are often given to relax the muscles of the iris. Sometimes injections of cortisone into the affected eye are necessary when the inflammation is severe. Heart disease in patients with ankylosing spondylitis, such as heart block, may require a pacemaker placement or medications for congestive heart failure.

Finally, orthopedic surgery may be required when there is a severe disease of the hip joints and spine.