Spondyloarthritis is a group of inflammatory diseases that cause arthritis. You also may hear it called spondyloarthropathy or, for short, SpA. It’s different from other kinds of arthritis because it also causes inflammation in areas called entheses where ligaments and tendons attach to bones. Ligaments are tissues that connect your bones to one another, and tendons are tissues that connect your bones to your muscles.
There are a number of conditions in the spondyloarthritis family. They include:
• Ankylosing spondylitis (also called “spondylitis”): This is the most common form. It affects the joints and ligaments along your spine and causes pain and stiffness that start in your lower back and may spread into your upper spine, chest, and neck. Eventually, the joints and bones there can fuse and make your spine stiffen into a C-shape. That leads to a hunched posture.
• Reactive arthritis: This starts with an infection of your intestine or urinary tract. An immune reaction may follow that can cause pinkeye (conjunctivitis) and can cause rash oral ulcers and urinary tract inflammation as well as arthritis. This condition used to be known as Reiter’s syndrome.
• Psoriatic arthritis: Some people who have skin disease psoriasis also get this type of arthritis. With it, your body’s immune system attacks healthy joints and skin by mistake. That can cause joint pain, stiffness, and swelling in your hands and feet as well as the spine.
• Enteropathic arthritis: This inflammatory arthritis affects some parts of your digestive tract. It can be associated with a number of inflammatory bowel diseases, including Crohn’s disease and ulcerative colitis.
The different types of spondyloarthritis may have:
• Back pain
• Digestive issues
• Inflammation of the aortic heart valve
• Pain or swelling in other joints, including your hips, knees, ankles, feet, hands, wrists, elbows, and shoulders
• Psoriasis skin rash
• Swelling along with the tendons of your fingers or toes (“sausage fingers”)
• Swelling, pain, or redness in the part of an eye
Spondyloarthritis tends to be inherited. Scientists have linked about 30 genes to the condition. The biggest culprit is one called HLA-B27. It’s found in 90% of people who have the most common form of spondyloarthritis (ankylosing spondylitis)