What is 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. It can be painful to move or tender to touch. These problems happen because of the inflammation in the joint. When the arthritis is in a large, joint, such as the hip or along the spine, the swelling can be hard to see on exam., or sometimes not able to be seen, on physical exam. This means imaging such as an ultrasound, or a CT or MRI is needed to look at the joint. In SpA, inflammation can happen where tendons attach our muscles to bones. It can also happen where ligaments attach to bones. These areas are called enthesis. Inflammation of an enthesis can cause pain, tenderness and swelling.
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 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). Learn more about juvenile idiopathic arthritis (JIA).
SpA most often happens in people who are 20-30 years old. SpA can happen in the teen years. If you have been diagnosed with AS by the time you are 45, you likely won’t be diagnosed with AS. The 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. The cause is not known. But the risk for being diagnosed with SpA is partly genetic.
Signs and Symptoms of SpA
SpA is a clinical finding / type of arthritis, which raises our suspicion to investigate if the child has one of these listed conditions. If you have SpA, it does not mean you definitely have or will have one of these conditions, but it needs to be evaluated.
The conditions that fall under the SpA grouping include:
-
Juvenile Idiopathic Arthritis- Enthesitis-related arthritis subtype
- Juvenile ankylosing spondylitis (JAS)
- Reactive arthritis
- Arthritis associated with inflammatory bowel disease (IBD) and psoriasis (see table 1)
Each will be looked at on its own, as they differ in crucial ways.
Juvenile Idiopathic Arthritis (JIA)- Enthesitis-Related Arthritis subtype (ERA)
Often, ERA starts as arthritis in the large joints of the lower extremities. This affects the hips and knees. It is common to have pain and feel tender where tendons or ligaments attach to bones. Common sites for inflammation are:
- The heel
- Top and bottom of the kneecap (patella)
- Ball of the foot
- Bottom of the foot at the heel
- Mid-foot zone
Arthritis is not common in the elbows and wrists, but it does occur in the shoulders. Patients with ERA may have inflammation in other parts of their body. Eye inflammation (called anterior uveitis) occurs in about half of patients.
Uveitis with ERA causes pain and redness. Redness and pain are not common in other types of arthritis that affect the eyes.
Juvenile Ankylosing Spondylitis (JAS)
JAS is a more developed form of SpA in children. In JAS, the child has developed arthritis in the lower back in r 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, the child is diagnosed with ERA. In studies looking at children who developed JAS at some point had arthritis first, that looked like ERA, they were more likely to have had lower extremity arthritis and pain. They also had tender feeling where tendons or ligaments attach to bones during the first year of their illness. The foot was included.
We diagnose the child with ERA if they have symptoms present, but not back pain. Some studies say that up to 50 percent of these children will have complete JAS with time. This depends on genetic factors. We are not able to predict who with ERA will or will not get JAS.
Reactive Arthritis (ReA)
Reactive arthritis (ReA) often occurs two to four weeks after an infection. This happens in some other part of the body, like the gastrointestinal (GI) tract, urinary tract, or the genitals. GI infections most often involve diarrhea, belly pain and cramping. They are caused by bacteria like salmonella. Infection in the urinary tract or genitals may not have a specific symptom (mostly in females). The inflamed joints do not have these bacteria. They are still the site where many inflammatory cells collect and cause symptoms for unknown reasons. ReA is more common in people with the genetic marker HLA-B27. This is a gene that is there in about 70 to 90 percent of patients with arthritis that affects the spine. In most children with ReA the arthritis is short-lived with all symptoms going away. Some children may have a more chronic course. Some patients may develop complete JAS over several years.
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 often linked to the HLA-B27 gene. Arthritis is seen in some but not all people who have the skin disease psoriasis.
Diagnosis of Spondyloarthritis
There are several signs and symptoms doctors use to diagnose SpA. This may come from a history, physical exam findings and abnormal X-rays or MRIs of your SI joints (See table 1 for definitions). Making this diagnosis can be hard. Some findings are not there when the disease starts but show up over time. Other symptoms 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. Even though most people with SpA have HLA-B27, many healthy people also have HLA-B27 and never have any joint problems. About four percent of healthy Caucasians have HLA-B27. 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. Treatment is 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 or eliminate the inflammation in the joint. This leads to decreased or absent symptoms and physical abnormalities in that joint for up to 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 few studies have been done. Your doctor should talk to you about this.
Another component of treatment is physical therapy and activity. This helps you stay flexible and get stronger. Activities like swimming are a good choice, as they do not put weight on your joints. Some types of shoe inserts or special shoes can be used to ease pain when there is arthritis in your foot. These can help with swelling under or on the back of your heel.
It is important 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 look at staying active as a lifestyle choice.
Long-Term Outlook
What will the future hold is one of the hardest questions to answer. Each person is different.
Making the right diagnosis is important since there are many types of Spas in children. Some studies where children with JAS were followed for about 15 years show they may not be able to do as much as others their age.
Other studies have shown very good outcomes. These studies have shown that more than 75 percent of patients were either working or still taking classes. Only 10 to 20 percent were disabled 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), call toll-free (United States only) 1-800-777-8189, or call 1-818-981-1616. For research questions, email (info@asresearch.org) or call toll-free (1-888-777-8189).
Table 1. Features of Juvenile 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 goes along with morning stiffness. It must happen for at least three months.
Synovitis
Swelling of the synovium, or the layer of cells lining the joint space. This leads to symptoms of arthritis. This 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
Psoriasis is a skin disease that causes a scaly, pink rash in patches on the face or scalp. It can occur in many locations on the body.
Inflammatory Bowel Disease
Crohn's disease or ulcerative colitis diagnosed by a doctor.
Buttock Pain
Past or current pain that rotates between either buttock.
Enthesopathy
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. Enthesitis refers to swelling at these sites.
Diarrhea
Sudden start of loose water-like stool within one month before the start of arthritis.
Sacroiliitis
Inflammation in one or both sacroiliac joints. This inflammation can cause stiffness, pain, tenderness, and limitation of motion in this joint. Inflammation can be seen on MRI or CT in early stages and on X-rays at later stages.
