Ankylosing spondylitis and other “seronegative spondylo-arthropathies”
This is a group of conditions which are related to each other and have some overlap and similarities. They represent auto immune diseases which are somewhat genetically determined. They are all much more common in individuals who have the HLA B27 gene. This gene is a particular variant of an immune system regulatory gene, and it is present in about 10% of the population. Those who have it are at increased risk of these autoimmune diseases.
The specific diseases are: sacroiliitis (arthritis of the joint between the sacrum and the iliac bones in the lower back), ankylosing spondylitis (arthritis of the joints between the spinal vertebrae, leading to fusion between them), reactive arthritis, inflammatory bowel disease and psoriatic arthritis. All of them are also associated with uveitis, most commonly acute anterior uveitis, presenting with sudden onset of eye discomfort, with variable combinations of redness, light sensitivity (photophobia), pain on “focusing in” and pain on eye movements, often with some blurring of the vision. The uveitis may be mild or severe, usually requiring several weeks of treatment to resolve, and rarely becoming chronic. Acute anterior uveitis is a medical emergency and early treatment may prevent permanent damage to important parts of the eye.
Many patients have symptoms of low back pain which are dismissed as trivial and are only diagnosed once they develop uveitis, pointing to a possible association. This type of uveitis usually occurs in young individuals (from teens to 40’s) but may occur at any age.
Typically, the back symptoms include stiffness and soreness of the lower back after inactivity, often worse after sleep and better with mobility. Patients with severe back symptoms sometimes have to wake up and move about in the middle of the night to relieve the pain. The problem may be diagnosed by physical examination supported by X ray examination of the sacro-iliac joint or the lower back.