Ankylosing spondylitis is a type of arthritis of the spine. It causes swelling between your vertebrae, which are the disks that make up your spine, and in the joints between your spine and pelvis. Ankylosing spondylitis is an autoimmune disease. This means your immune system, which normally protects your body from infection, attacks your body’s own tissues. The disease is more common and more severe in men. It often runs in families.
The disease course is highly variable, and while some individuals have episodes of transient back pain only, others have more chronic severe back pain that leads to differing degrees of spinal stiffness over time. In almost all cases the disease is characterized by acute painful episodes and remissions (periods where the problem settles). It is important to note that the course of ankylosing spondylitis varies greatly from person to person. So too can the onset of symptoms. Although symptoms usually start to appear in late adolescence or early adulthood (ages 17-35), the symptoms can occur in children or much later.
The pain normally becomes persistent (chronic) and is felt on both sides, usually persisting for at least three months. Over the course of months or years, the stiffness and pain can spread up the spine and into the neck. Pain and tenderness spreading to the ribs, shoulder blades, hips, thighs and heels is possible as well.
Ankylosing spondylitis is two to three times more common in males than in females. In women, joints away from the spine are more frequently affected than in men. Ankylosing spondylitis affects all age groups, including children. The most common age of onset of symptoms is in the second and third decades of life.
Signs and Symptoms of Ankylosing Spondylitis
Your condition may change over time, with symptoms getting worse, improving or completely stopping at any point. Early signs and symptoms may include pain and stiffness in your lower back and hips a” which is often worse in the morning, at night and after periods of inactivity. Over time, the pain and stiffness may progress up your spine and to other joints, such as those in your hips, shoulders, knees and feet.
The disease starts with hip or low back pain that comes and goes and is worse at night, in the morning, or after inactivity.
The pain and stiffness are usually worse early in the morning and after resting, but improve with exercise as the day progresses.
Involvement of the hips and shoulder joints is possible but is more common in juvenile-onset ankylosing spondylitis (patients with onset before age 16 years).
The back pain is dull and is felt in the hips and buttocks. The pain often begins on one side (unilateral) and comes and goes (intermittent), but as the disease progresses, it becomes more persistent and affects both sides (bilateral).
Children, generally boys, occasionally also develop symptoms in their hips and knees, however. While beginning in the lower back, the pain and stiffness will gradually move up through the spine and into the neck. The inflammation that causes pain can also cause the joints in the spine to fuse, making standing or walking difficult.
Coughing or straining may make it worse. Rest does not make it better. Instead, exercise usually eases the pain. The pain tends to be worse first thing in the morning. Lying in bed after waking is often uncomfortable. The pain tends to ease as the day goes on. The middle (chest part) of the spine may become affected. If this occurs the joints between the ribs and the spine may also become painful.