Juvenile Spondyloarthritis

Spondyloarthritis (SpA) is a type of arthritis that involves joints along the spine as well as hips, shoulders, knees and ankles.

When there is arthritis in a joint, it can be warm and swollen and painful to move or tender to touch.  These problems are a direct result of the inflammation in the joint.  When the arthritis is in a large, deep-seated joint, such as the hip or along the spine, the swelling can be difficult or impossible to see on physical exam and requires use of radiology imaging such as CTs or MRIs.  In SpA, an additional location in the body where inflammation often occurs is where tendons attach our muscles to bones, or where ligaments attach to bones (these areas are called enthesis; plural entheses).

SpA can occur in children and adults. There are many forms of SpA.  The most advanced form of SpA is known as ankylosing spondylitis (AS). In patients with AS it is required that there is evidence of involvement of the spine on X-ray.  When this occurs in children it is called juvenile ankylosing spondylitis (JAS).   A far more common type of SpA in children is called enthesitis-related arthritis (ERA).  Additional information about ERA is provided below and in the information about juvenile idiopathic arthritis.

SpA usually develops in people who are 20-30 years old, but one out of every six or seven 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 number of individuals with SpA is not known, it occurs in about five to nine out of every 1,000 people. Since about half of these people have AS, there are close to 500,000 cases in the United States alone.

SpA affects people all around the world, and although its exact cause is not known, the risk for developing SpA is in part due to a person’s genetic makeup.

There are several conditions that fall under the SpA category, including:

  • Enthesitis-related arthritis
  • Juvenile ankylosing spondylitis (JAS)
  • Reactive arthritis
  • Arthritis associated with inflammatory bowel disease (IBD) and psoriasis (see table 1)

Since they differ in important ways, each will be considered separately.

Enthesitis-Related Arthritis (ERA)

In many children and adolescents, 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 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. In studies looking at children who eventually developed JAS but initially had arthritis that looked just like ERA, it was found that they were more likely to have had lower extremity arthritis and pain and tenderness where tendons or ligaments attach to bones during the first year of their illness, and frequent involvement of the foot (tarsitis).

Thus when many of the symptoms are present but the child has yet to develop back pain (sacroiliitis), we typically call it ERA. Some studies suggest that as many as 50 percent 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 (ReA) usually occurs two to four 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 percent to 90 percent 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.

There are a number of signs and symptoms doctors use to diagnose SpA. This information may come from a history of how your symptoms affect you, your physical exam findings and abnormal X-rays of your sacroiliac joints (See table 2 for definitions). Making this diagnosis can be difficult as some findings are not present when the disease starts, but develop over time, while others may never appear. This is particularly true in children, where lower back pain, sacroiliitis and abnormal X-ray findings are less common in the early stages.

Your doctor may do a test for HLA-B27 if he or she thinks you have SpA.  But remember, even though most people with SpA have HLA-B27, many healthy individuals also have this genetic marker and never develop any joint problems.  For example, about 4 percent of healthy Caucasians are positive for HLA-B27.  That means that even if you have HLA-B27, you may not have SpA or JAS. Other symptoms and signs of the disease must be present for the diagnosis to be made. When used along with other information, the HLA-B27 test can be quite helpful, particularly in recognizing JAS.

Children with either ERA or JAS are treated like children with JIA in many ways, although treatments are tailored to the severity of your disease and where it is most prominent. Doctors most often begin the treatment with nonsteroidal 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 six 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.

Medications called biologics have been shown to be highly effective in reducing the inflammation in the joints, which then improves the symptoms in adults with SpA. These drugs also work well in children with JIA, and are expected to work for SpA in children, although fewer studies have been done. Your doctor should discuss this with you.

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 (tarsitis) 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.

Faced with a newly diagnosed chronic disease, most people want to know what the future will hold. In our experience this is one of the most difficult questions to answer because everybody is different. Making the correct diagnosis is very important since there are several types of SpA in children. Some studies where children with JAS were followed for about 15 years suggest they may not be able to accomplish as much as others their age. However, other studies have emphasized very positive outcomes with more than 75 percent of patients either employed or still taking classes, and only about 10 percent to 20 percent being disabled even after 20 to 30 years. The outcome is probably even more favorable for other SpAs, since JAS tends to be more severe.  Very importantly, treatments continue to improve, especially the benefits seen with the recent biologics. Therefore, the future for children with SpA is very encouraging.

Individuals who want more information about SpA or are interested in contributing to genetic studies can contact the Spondylitis Association of America (SAA). For information, try the SAA web site, email (info@spondylitis.org) or call toll-free (United States only) 1-800-777-8189. The regular number is: 1-818-981-1616. For research questions, email (info@asresearch.org) or call toll-free (1-888-777-8189).

  • Enthesitis-related arthritis (ERA)
  • Juvenile ankylosing spondylitis (JAS)
  • Reactive arthritis (ReA)
  • Arthritis associated with inflammatory bowel disease (IBD)
  • Arthritis associated with psoriasis

Inflammatory Spinal Pain

Back pain developing before age 45 that is slow in onset, with symptoms improved by exercise and worsened by rest. This is accompanied by morning stiffness and generally must be of at least three months duration.

Synovitis

Inflammation of the synovium, or the layer of cells lining the joint space, which produces symptoms of arthritis; typically involving the lower limbs or shoulders in SpA.

Positive Family History

Parents, sisters and brothers, grandparents, aunts, uncles or cousins with any of the following: AS, psoriatic arthritis, acute uveitis, reactive arthritis or inflammatory bowel disease with arthritis.

Psoriasis

Psoriasis is a skin disease that causes a scaly, pink rash in patches on the face, scalp and over the knuckles.

Inflammatory Bowel Disease

Crohn's disease or ulcerative colitis diagnosed by a physician.

Buttock Pain

Past or current pain alternating between either buttock.

Enthesopathy

Past or current pain, or tenderness, where the Achilles tendon or plantar fascia insert on bone (back of heel or underneath heel). Enthesis is the general term for where a tendon or joint capsule inserts on bone, and enthesitis refers to inflammation at these sites.

Diarrhea

Abrupt onset of loose watery stool within one month prior to the onset of arthritis.

Sacroiliitis

Inflammation in one or both sacroiliac joints that is evident on X-rays.


Last Updated 10/2012