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 happen because of the inflammation (swelling) 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 hard to see, or sometimes not able to be seen, on physical exam. This means radiology imaging such as CTs or MRIs is needed. In SpA, swelling often also happens where tendons attach our muscles to bones or where ligaments attach to bones. These areas are called enthesis (plural entheses).

SpA can happen in children and adults. There are many forms of SpA.

The most advanced form of SpA is ankylosing spondylitis (AS). To have AS there must be proof of that the spine is involved on the X-ray. When this happens in children it is called juvenile ankylosing spondylitis (JAS).

A far more common type of SpA in children is called enthesitis-related arthritis (ERA). See details below in "Signs and Symptoms." 

SpA most often happens in people who are 20-30 years old, but one out of each six or seven cases starts in the teen years. If you have not gotten AS by the time you are 45, chances are good that you won't. The exact number of people with SpA is not known. It happens in about five to nine out of each 1,000 people. Since about half of these people have AS, there are close to 500,000 cases in the US alone.

Causes of SpA

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

Signs and Symptoms of SpA

There are conditions that fall under the SpA grouping. These include:

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

Each will be looked at on its own, as they differ in crucial ways.

Enthesitis-Related Arthritis (ERA)

In many children and adolescents, ERA starts as arthritis in the large joints of the lower extremities, mainly the hips and knees. It is also common to have pain and feel tender 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, mainly in the mid-foot zone (tarsitis), is seen. It is not common 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 where the child needs to have developed arthritis in the lower back in either the spinal joints or the sacroiliac joints (sacroiliitis).

Diagnosing JAS can be hard if the spine and/or lower back are not involved when other symptoms start.  Since the back concerns may not occur for many years after other symptoms have begun, in this case the child is said to have ERA. In studies looking at children who developed JAS at some point but at first had arthritis that looked just like ERA, it was found that they were more likely to have had lower extremity arthritis and pain and tender feeling where tendons or ligaments attach to bones during the first year of their illness, and often including of the foot (tarsitis).

Thus when many of the symptoms are present but the child has yet to have back pain (sacroiliitis), we most often call it ERA. Some studies suggest that as many as 50 percent of these children will have complete JAS with time either in the late teen years or as an adult. This depends on genetic factors though, and we are not yet able to predict with certainty who with ERA will or will not get JAS.

Reactive Arthritis (ReA)

Reactive arthritis (ReA) most often occurs two to four weeks after an infection in some other part of the body like the GI tract, urinary tract or the genitals. GI infections most often involve diarrhea, belly pain and cramping, and are caused by bacteria like salmonella. Infection in the urinary track or genitals may not be associated with specific symptoms (chiefly in females). The inflamed joints do not have these bacteria, but are still the site where many inflammatory cells collect and cause symptoms for reasons that are unknown. Like other forms of SpA, getting ReA is much more common in people with the genetic marker HLA-B27. This is a gene that is there in about 70 percent to 90 percent of patients with arthritis that affects the spine. ReA in children can be short-lived with full 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 hard to predict.

Arthritis Associated with Inflammatory Bowel Disease (IBD) or Psoriasis

Arthritis can happen with either type of IBD − Crohn's disease or ulcerative colitis. The arthritis can involve joints in the arms or legs and/or spinal joints and the sacroiliac (SI). When the spine or SI joints are involved it is most often linked to the HLA-B27 gene. Arthritis is also seen in some but not all people who have the skin disease psoriasis.

Diagnosis of Spondyloarthritis

There are a number of signs and symptoms doctors use to diagnose SpA. This may come from a history of how your symptoms affect you, your physical exam findings and abnormal X-rays of your SI joints (See table 2 below for definitions). Making this diagnosis can be hard as some findings are not there when the disease starts, but show up over time, while others may never appear. This is very 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 they think you have SpA. But know that even though most people with SpA have HLA-B27, many healthy people also have HLA-B27 and never have any joint problems. For example, about 4 percent of healthy Caucasians have 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 there for the diagnosis to be made. When used with other information, the HLA-B27 test can be very helpful in spotting JAS.

Treatments for Spondyloarthritis

Children with ERA or JAS are treated like children with JIA in many ways, but treatments are tailored to how severe their disease is and where it is most pronounced. Doctors most often start the treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) such as Naprosyn or Mobic. Arthritis in the knees, ankles and hips can often be treated with a shot of corticosteroids into the joint space. This helps reduce the swelling. Often a single shot of corticosteroids into a joint relieves most or all of the swelling 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). Your doctor will need to do blood tests at routine time frames to look for side effects from these treatments.

Medicine called biologics have been shown to be very good at reducing the swelling in the joints. This improves the symptoms in adults with SpA. These drugs also work well in children with JIA. They are also believed to work for SpA in children, but fewer studies have been done. Your doctor should discuss this with you.

Another vital component of treatment is physical therapy and activity to help you stay flexible and get stronger. Activities like swimming are very good, as they do not put weight on your joints. Some types of shoe inserts or even special shoes can be used to ease pain when there is arthritis in your foot (tarsitis). These can also help with swelling under or on the back of your heel.

It is vital for you to learn as much as possible about SpA. Though symptoms and the amount of swelling may come and go with time and treatment, this is not a disease that can be cured at this time. Those who cope the best and continue to function at a high level are those who approach staying active as a lifestyle choice, rather than as a disease therapy only done when symptoms worsen.

Long-Term Outlook

Faced with a newly diagnosed chronic disease, most people want to know what the future will hold. We have found this is one of the hardest questions to answer because each person is different.

Making the right diagnosis is vital since there are many types of SpA in children. Some studies where children with JAS were followed for about 15 years suggest they may not be able to do as much as others their age.

Other studies have pointed out very good outcomes. These studies have shown that more than 75 percent of patients were either working or still taking classes, and only about 10 percent to 20 percent were disabled even after 20 to 30 years.

The outcome is likely even better for other SpAs, since JAS tends to be more severe. Treatments continue to get better. There have been many benefits seen with the recent biologics. The future for children with SpA is very hopeful.

Research Resources

If you want more information about SpA or want to contribute to genetic studies, contact the Spondylitis Association of America (SAA). For information, you can visit the SAA website, 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).

Table 1. Juvenile Spondyloarthritis

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

Table 2. Features of Spondyloarthritis

Inflammatory Spinal Pain

Back pain that happens before age 45, that is slow in onset and gets better with exercise and worse with rest. This is accompanied by morning stiffness and for the most part must happen for at least three months.


Swelling of the synovium, or the layer of cells lining the joint space. This leads to symptoms of arthritis. This most often involves the lower limbs or shoulders in SpA.

Positive Family History

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


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 doctor.

Buttock Pain

Past or current pain that rotates between either buttock.


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


Sudden start of loose water-like stool within one month before the start of arthritis.


Swelling in one or both sacroiliac joints that is clear on X-rays.

Last Updated 07/2018

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The Rheumatology Clinic at Cincinnati Children’s provides diagnosis, education, treatment and follow-up for children with various rheumatic diseases. For more information, call 513-636-4676.