What is ankylosing spondylitis?
Ankylosing spondylitis (AS) is a painful, often progressive and potentially debilitating chronic inflammatory condition that tends to affect young people, mainly men, in their late teens and twenties.1 It is commonly referred to as arthritis of the spine.
AS initially begins with persistent lower back pain and stiffness which over time, become progressively worse, particularly at night as a result of local inflammation of the soft tissue supporting bone.1
The symptoms include:
Slow or gradual onset of back pain and stiffness over weeks or months, rather than hours or days (seldom an acute back pain)
Early-morning stiffness and back pain, wearing off or reducing during the day with movement
Feeling better after exercise and feeling worse after rest
Sleep disturbance due to pain, particularly second half of the night
Arthritis, in large joints, especially the legs, together with pain in the joints of the lower back particularly at night or on waking
Persistence of above symptoms for more than three months
Pain relieved for a time after a shower or bath
Symptoms begin typically in late teens or 20's
Inflammation occurs where ligaments or tendons are attached to the bone causing damage at the site of attachment. When the healing process begins, new bone develops replacing the elastic tissue of the ligaments or tendons.1,2
Recurrence of this inflammatory process leads to further new bone formation which gradually results in the restriction of joint movement. When these disease processes occur in the spine, irreversible damage is caused as the vertebrae (joints of the spine) become fused together.1,2
AS varies between individuals in the way it progresses and symptoms will differ in severity, however most patients will experience flare-ups of inflammation periodically. 2 Disease progression can lead to fusion of the spine; causing loss of mobility and loss of function. In advanced stages of the disease or severe cases that are left untreated, spinal mobility and flexibility may become so reduced that the patient becomes progressively stooped (bent-over) making it increasingly difficult for the individual to move freely and carry out their usual daily activities.2,3 AS can lead to decreased daily activity, loss of work productivity and reduced quality of life in those affected. 1
Although AS is a form of arthritis which primarily affects the spine, other joints and organs of the body can also be affected such as the hips, shoulders, knees, eyes, lungs, bowel, skin, and heart.2 Up to 40 per cent of people with AS will at some point develop a severe inflammation inside one or both of their eyes, this is known as iritis or uveitis and it causes redness and blurred vision. 2,3
AS sometimes overlaps with other conditions including reactive arthritis, psoriasis and inflammatory bowel disease. These overlapping conditions exist under the umbrella term ‘spondyloarthritis’.3,4
1. Sieper J. et al. Ankylosing spondylitis: an overview. Ann Rheum Dis. 2002;61(Suppl III):iii8-iii18
2. National Ankylosing Spondylitis Society. Guidebook for `Patients: A Positive Response to Ankylosing Spondylitis. March 2007
3. Elyan M, Khan MA. Diagnosing Ankylosing Spondylitis. Rheum. 2006:33 (Suppl 78):12-23
4. Sieper J, Braun J. Clinician’s Manual on Ankylosing Spondylitis. London: Current Medicine Group.