What Is Oligoarticular Juvenile Idiopathic Arthritis?

Oligoarticular juvenile idiopathic arthritis is a type of juvenile idiopathic arthritis (JIA). JIA is a group of disorders that causes arthritis (stiff, swollen, painful joints) in children.

Children with oligoarticular (ol-ih-go-ar-TIK-yuh-lur) juvenile idiopathic arthritis (oligoarticular JIA) have arthritis in fewer than 5 joints in the first 6 months of the disease. In some children, more joints become involved over time. Problems with the eyes and bone growth also can happen.

Treatments can help with symptoms, so children can live a full and active life. The symptoms can go away for a time (called remission). In some kids, the condition goes away permanently.

What Are the Signs & Symptoms of Oligoarticular Juvenile Idiopathic Arthritis?

Children with oligoarticular JIA have arthritis in fewer than 5 joints at first. Most often, it happens in large joints like the knees, ankles, and elbows. Kids with arthritis often complain of stiffness after rest, like in the morning or after a nap. They may not also have pain and the joints might not show obvious swelling.

After the first 6 months of illness:

• Some kids don’t get arthritis in other joints. This is called persistent oligoarthritis.
• Some kids do get arthritis in more joints. This is called extended oligoarthritis.

Other problems that can happen include:

• (inflammation inside the eye)
• problems with jaw growth if arthritis is in the jaw joint
• if arthritis is in the knee, leg length discrepancy (one leg is longer than the other) 
• short stature (being shorter than other kids the same age)

What Causes Oligoarticular Juvenile Idiopathic Arthritis?

Oligoarticular JIA is an autoimmune illness. This means that the body’s immune system, which normally attacks germs, mistakenly attacks the joints. This causes inflammation (swelling and irritation) in the joints and other problems.

The condition usually starts when a child is 2–3 years old. It is more common in girls.

Doctors don’t know exactly why kids and teens get JIA. “Idiopathic” means “from an unknown cause.” It can run in families but often does not. It’s likely due to a combination of:

• genetic (inherited) causes 
• the way the immune system responds to infection and illness
• a trigger, such as an infection

How Is Oligoarticular Juvenile Idiopathic Arthritis Diagnosed?

To diagnose oligoarticular JIA, doctors:

• ask about symptoms
• do an exam
• ask whether other family members have had similar problems
• do X-rays or other imaging studies to look inside the joints
• order blood tests to check for:
  • anemia or other blood problems
  • inflammation in the body
  • markers for some types of arthritis or autoimmune illnesses

Sometimes, an orthopedic surgeon (bone doctor) takes samples of joint fluid or synovium (the lining of the joints). The sample is sent to a lab for testing.

How Is Oligoarticular Juvenile Idiopathic Arthritis Treated?

Oligoarticular JIA is treated by a care team that includes:

• a rheumatologist (for problems with joints and connective tissue)
• a primary care doctor (such as a pediatrician or family medicine doctor)
• a physical therapist
• an ophthalmologist (eye doctor)

Treatment goals are to ease pain and inflammation, improve strength and flexibility, and prevent joint damage. Treatment usually includes medicines to ease inflammation (taken by mouth and injected into the joint), eye drops for uveitis, physical therapy, and exercise.

Sometimes surgery is needed for damaged joints.

How Can Parents Help?

Oligoarticular JIA usually is a lifelong disease, but treatments can help ease pain, keep kids active, and prevent long-term joint damage. To help your child:

• Make sure your child takes all medicines exactly as directed.
• Go to all regular eye doctor visits, even if your child has no symptoms of pain or redness in the eyes.
• Work with the physical therapist to develop a regular exercise program. This will help keep your child’s muscles strong and flexible.
• Learn about JIA with your child. Your care team is a great resource. You also can find more information and support online at:
  • The Arthritis Foundation