Spondyloarthritis (SpA) is a type of arthritis that involves joints along the spine as well as hips, shoulders, knees and ankles.
SpA can occur in children and adults. SpA usually develops in people who are 20-30 years old, but one out of every 6 or 7 cases begins in the teenage years. If you haven't developed AS by the time you're 45, chances are good that you won't.
Although the exact cause of SpA is not known, the risk for developing SpA is in part due to the person’s genetic makeup.
When there is arthritis in a joint it can be warm, swollen, painful to move or tender to touch. These manifestations are a direct result of the inflammation in the joint. In SpA, the inflammation often occurs where tendons attach our muscles to bones, or where ligaments attach bones together.
There are several conditions that fall under the SpA category, including:
Since they differ in important ways, each will be considered separately.
Enthesitis Related Arthritis (ERA)
In many patients, ERA begins as arthritis in the large joints of the lower extremities, particularly the hips and knees. It is also common to have pain and tenderness due to inflammation where tendons or ligaments attach to bones. This is called “enthesitis”. Common sites for this inflammation are at the heel, the top and bottom of the kneecap (patella), the 'ball' of the foot, and bottom of the foot at the heel (plantar fascia). Also, in some patients with ERA, inflammation in the joints of the foot, particularly in the mid-foot region (tarsitis), is seen. It is uncommon for arthritis to occur in the elbows and wrists, but it does occur in the shoulders. Sometimes patients with ERA will have inflammation in other parts of their body. Eye inflammation (anterior uveitis) occurs in approximately one half of patients. Unlike the inflammation in the eyes seen in other types of arthritis, the uveitis seen in ERA almost always causes pain and redness.
Juvenile Ankylosing Spondylitis (JAS)
JAS is a more fully developed form of SpA in children that requires the child to have developed arthritis in the lower back in either the spinal joints or the sacroiliac joints (sacroiliitis).
Diagnosing JAS can be difficult if the spine and/or lower back are not involved when other symptoms begin. Since the back involvement may not occur for many years after other symptoms have begun in this situation the child is said to have ERA. Some studies suggest that as many as 50% of these children will develop complete JAS with time either in late adolescence or as an adult. However, this depends on genetic factors, and it is not yet possible to predict with certainty who with ERA will or will not develop JAS.
Reactive arthritis (ReA)
Reactive arthritis usually occurs 2-4 weeks after an infection in some other part of the body like the gastrointestinal tract, urinary tract or the genitals. Gastrointestinal infections are usually accompanied by diarrhea, abdominal pain, and cramping, and are caused by bacteria like Salmonella. Infection in the urinary track or genitals may not be associated with specific symptoms (especially in females). The inflamed joints do not contain these bacteria, but are still the site where many inflammatory cells accumulate and cause symptoms for reasons that are unknown. Like other forms of SpA, development of ReA is much more common in people with the genetic marker HLA-B27 (This is a gene that is present in about 70-90% of patients with arthritis that affects the spine). ReA in children can be short-lived with complete resolution of symptoms, or may continue with a more chronic course. Some patients may go on to develop complete JAS over several years, but again this is difficult to predict.
Arthritis Associated with Inflammatory Bowel Disease (IBD) or Psoriasis
Arthritis can occur as a manifestation of either type of IBD - Crohn's disease or ulcerative colitis. The arthritis can involve joints in the arms or legs and/or spinal joints including the sacroiliac (SI). When the spine or SI joints are involved it is usually associated with the HLA-B27 gene. Arthritis is also seen in some but not all people who have the skin disease psoriasis.
Doctors most often begin the treatment with non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naprosyn. Arthritis in the knees, ankles and hips can frequently be treated with an injection of corticosteroids into the joint space to help lessen inflammation. Usually a single injection of corticosteroids into a joint results in complete or nearly complete resolution of the inflammation in the joint for at least 6 months.
Both sulfasalazine and methotrexate have been helpful for patients with SpA and peripheral arthritis. These are called disease modifying anti-rheumatic drugs (DMARDs) and they require that your doctor obtain blood tests at regular intervals to look for side effects from the treatments.
Another very important component of treatment is physical therapy and activity aimed at maintaining flexibility and improving strength. Activities like swimming are particularly good, as they do not put weight on your joints. Different types of shoe inserts or even special shoes can be used to relieve pain when there is arthritis in your foot or if you have inflammation under or on the back of your heel.
It is extremely important for patients and families to learn as much as possible about SpA. Although symptoms and the amount of inflammation may come and go with time and treatment, this is not a disease that can be cured at this time. Patients who cope the best and continue to function at a high level are those who approach maintaining physical activity as a lifestyle choice, and not simply depending upon disease therapy that can be attempted when symptoms worsen.