What Is Juvenile Ankylosing Spondylitis?

Ankylosing spondylitis is a type of arthritis. It affects areas on the lower back and spine where the muscles, tendons and ligaments attach onto bones. The condition’s name derives from its symptoms: “ankylosing” means stiff or rigid; “spondyl” means spine; “itis” refers to inflammation. 

In teenagers and children, the condition is referred to as juvenile ankylosing spondylitis (JAS).

Juvenile ankylosing spondylitis may lead to inflammation of the spine and large joints, resulting in pain and stiffness. The condition has the potential to create new bone formation across joints in the spine and/or lower back. This formation essentially fuses the joint(s) together, resulting in a restricted range of motion. 

Juvenile ankylosing spondylitis is abundantly more common in boys than girls. It is unlikely for younger patients to show symptoms before the age of 18. Usually, signs of the condition occur between the ages of 17 and 35. Only about 10-20% of people will show symptoms before the age of 18. JAS is a chronic condition. Some affected will have inactive periods where the disease is in remission. Others may have ongoing symptoms. 

Juvenile ankylosing spondylitis is categorized as a multifactorial condition, meaning that many factors are involved in producing the condition. Therefore, researchers are not exactly sure what causes it. However, some information is known: it takes the combination of both parents’ genes and unknown external factors to produce the condition. Because of this, ankylosing spondylitis tends to run in families. 

HLA antigens are a group of genes that can indicate whether a child will develop a certain disease. There is an antigen correlated with juvenile ankylosing spondylitis called HLA-B27. Only a very small number of people with the antigen will develop juvenile ankylosing spondylitis, but many children with juvenile ankylosing spondylitis have HLA-B27. If your child has HLA-B27, they may have an increased chance of developing juvenile ankylosing spondylitis. However, just because the antigen is present, does not mean your child has the condition. 

The symptoms of juvenile ankylosing spondylitis tend to come and go and can vary in different individuals, but some of the most common include: 

• Pain in the back, joints, buttocks, thighs, heels, or shoulders 
• Early morning stiffness 
• Slouched posture 
• Enthesitis (pain at the site of attachment of muscles, ligaments, and/or tendons to the bone) 
• Swelling of large joints, particularly in the legs 
• Eye pain, redness, sensitivity to light 
• Loss of appetite 
• Anemia 
• Fatigue 
• Fever 
• Weight loss 

Many symptoms of juvenile ankylosing spondylitis may resemble other diseases and medical conditions. To receive an accurate diagnosis, schedule a consultation appointment with the experts at Gillette Children’s.  

Due to the symptoms being similar to other conditions, juvenile ankylosing spondylitis can be hard to diagnose. At Gillette Children’s, clinical experts use a variety of diagnostic tests to diagnose JAS and any other possible complications. 

Your healthcare provider will give your child a physical exam and ask about your child’s symptoms and medical history. Other diagnostic tests your child’s provider may order include: 

• X-rays: this exam uses radiation to create images of tissues in the body. To diagnose JAS, images of the spine and pelvis are taken. The results can show changes in the spine and joints. Early onset changes may not be visible. Gillette utilizes traditional x-ray equipment as well as a specially designed low-radiation EOS X-Ray Imaging for children who might need frequent x-rays.
• Other imaging tests: other exams, such as an MRI, that create images of the body may be used.
• Blood tests: While there is no juvenile ankylosing spondylitis-specific test, your provider may order blood tests to identify inflammation or autoimmune conditions your child is experiencing.

At Gillette Children’s, our Spine Institute is devoted to the research and treatment of a variety of spine health conditions. A treatment plan tailored to your child’s needs will be made by our experts after considering your child’s symptoms, age, and general health. Treatment recommendations may include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen to reduce pain and swelling.
• Short-term use of corticosteroids (oral steroids) to reduce inflammation.
• Disease-modifying antirheumatic medicines (DMARDs) to slow inflammation
• Biologic medications to improve arthritis symptoms all over the body
• Regular exercise, especially exercises that strengthen the back.
• Physical therapy

If juvenile ankylosing spondylitis is left untreated, complications can arise. Count on the board-certified spine providers at Gillette Children's to create an ongoing treatment plan that fits your child’s needs.

Do you believe your child may have ankylosing spondylitis or another complex or rare condition? Request a Pediatric Expert Consult today!