Ankylosing spondylitis a form of Spondyloarthritis, is a chronic, inflammatory arthritis and autoimmune disease. It mainly affects joints in the spine and the sacroilium in the pelvis, and can cause eventual fusion of the spine.
It is a member of the group of the spondyloarthropathies with a strong genetic predisposition. Complete fusion results in a complete rigidity of the spine, a condition known as bamboo spine.
Signs and symptoms
The typical patient is a young male, aged 18–30, when symptoms of the disease first appear, with chronic pain and stiffness in the lower part of the spine or sometimes the entire spine, often with pain referred to one or other buttock or the back of thigh from the sacroiliac joint.
Men are affected more than women by a ratio about of 3:1, with the disease usually taking a more painful course in men than women. In 40% of cases, ankylosing spondylitis is associated with an inflammation of the eye (iridocyclitis and uveitis), causing redness, eye pain, vision loss, floaters and photophobia. Another common symptom is generalized fatigue and sometimes nausea. Less commonly aortitis, apical lung fibrosis and ectasia of the sacral nerve root sheaths may occur. As with all the seronegative spondyloarthropathies, lifting of the nails (onycholysis) may occur.
When the condition presents before the age of 18, it is relatively likely to cause pain and swelling of large limb joints, particularly the knee. In pre-pubescent cases, pain and swelling may also manifest in the ankles and feet, where calcaneal spurs may also develop. The spine may be affected later on.
Pain is often severe on rest, and improves with physical activity, but many experience inflammation and pain to varying degrees regardless of rest and movement.