Running, leaping, climbing—and any other form of movement or play—come naturally to children. Unfortunately, for those with a condition called juvenile idiopathic arthritis (JIA), joint inflammation (swelling) and stiffness can make these activities painful.  

There are more than 100 different rheumatic diseases, which can cause pain, swelling, and stiffness in joints and bones, and affect organs or connective tissues (muscles, tendons, and ligaments). JIA (formerly known as juvenile rheumatoid arthritis) is a common type of rheumatic disease that occurs during childhood.

Most rheumatic diseases are autoimmune disorders, which means the body’s immune system mistakenly attacks healthy cells and tissues. With JIA, the immune system specifically targets the lining of the joints. This creates inflammation and can result in a large variety of symptoms ranging from fever, rash, and lymph node swelling to more severe manifestations including an inability to move.

A healthy immune system does two jobs, explains Ian Ferguson, MD, a Yale Medicine pediatric rheumatologist. 

“It needs to ramp up and attack viruses or bacteria that threaten your body, and it also needs to settle back to normal after the threat is cleared,” he says. “When you have an autoimmune disease, the immune system keeps attacking, but now it’s attacking without purpose. It turns on you, and areas can be damaged. And with JIA, that means you keep having symptoms. You feel pain and don’t move as well as you should be able to.”

Because JIA primarily affects the joints, the inflammation can hinder bone development, and inflammation that limits movement can affect the child’s physical and emotional development. Autoimmunity can affect the entire body, and in rare cases JIA can cause problems with other organs. 

Fortunately, many therapies can be helpful, resulting in either permanent remission, meaning the disease is no longer active (with the use of medication), or quiescence, meaning there are no symptoms (after finishing the medication course). “Our goal is for children to be symptom-free, and with many medications, this is possible,” Dr. Ferguson says.

Juvenile idiopathic arthritis is a chronic, inflammatory disease that affects the musculoskeletal system of children. An estimated 300,000 children in the United States have arthritis, and JIA is the most common form of childhood arthritis. Diagnosis is made when there are clinical signs and symptoms that last for more than six weeks and the person is under the age of 16.

There are six different types, or categories, of JIA. Although each type has a different pattern of involvement and prognosis, they are similar in terms of treatment. It can be helpful to categorize the subtype of arthritis, but there can be considerable overlap in the clinical presentation, and symptoms can change and develop with time. Therefore, close observation is warranted.

• Oligoarticular JIA: This is the most common form of JIA, and is typically seen in young girls. Four or fewer joints are affected during the first six months of the disease, and the knee is the most frequently affected joint. If no more joints are affected after six months, oligoarticular JIA is further classified as “persistent.” If more joints are affected after six months, it is considered “extended.”
• Polyarticular JIA: The second most common form of JIA, this type affects five or more joints in the first six months of onset. It often begins in late childhood. Polyarticular JIA is divided into two types: RF (rheumatoid factor) negative and RF positive. RF is an antibody that is present in the blood of people with rheumatoid arthritis. The RF-positive type is most common in adolescent girls and can have symptoms similar to adult rheumatoid arthritis.
• Enthesitis-related Arthritis: In this type of JIA, a child has arthritis in addition to painful inflammation at the sites where tendons and ligaments insert into the bone. Enthesis-related arthritis commonly affects the hips, knees, and feet.
• Psoriatic Arthritis: With this type of JIA, children have arthritis as well as psoriasis, an autoimmune condition that can cause red, scaly patches on the skin. Other psoriatic arthritis symptoms can include inflammation in toes or fingers, along with ridges in fingernails.
• Systemic Onset JIA: This subtype has the most severe presentation and affects about 10 percent of children with arthritis. It begins with recurring fevers that can be 103 degrees or higher and children develop other systemic symptoms such as rash, lymph node swelling, and severe elevation in the lab markers of inflammation. Arthritis can be severe and require stronger treatments than the other types.
• Undifferentiated Arthritis: The diagnosis of undifferentiated arthritis may be given to a child with symptoms of two or more JIA types above, or when symptoms don’t match any other type of JIA.  

The cause of JIA is unknown (idiopathic means relating to a disease for which there is no known cause), but research suggests genetics can be a factor. A small percentage of cases run in families, and you are 12 times more likely to develop JIA if your sibling has the disease. 

Persistent swelling, pain, tenderness, and stiffness in the joints are the most common symptoms of JIA. The knees, hands, and feet are usually the most affected, and symptoms are typically worse in the morning or after taking a nap. Swollen joints often become warm to the touch and moving affected joints may worsen the pain. This can make children reluctant to walk, or cause them to limp.

Additional symptoms can include the following:

• Blurred vision (due to inflammation of the inside of the eye, a common secondary area of involvement)
• High fever (often 103 degrees), which comes and goes for about two weeks, and is usually highest in the afternoon and evening but returns rapidly to normal
• Rash; rough, red spots on the skin; or salmon-colored patches with clear centers that appear on the trunk and upper legs and arms
• Growth and development problems. These can be related to abnormal growth in the skeleton due to the inflammation or reduced physical activity due to pain.

Most children with JIA go through periods where their symptoms improve or go away altogether, and times when they return and worsen. Children’s symptoms also depend on the type of JIA they have and their age, Dr. Ferguson explains.

“Younger children are more likely to be affected in their big joints—the knees and ankles,” he says. “Older children and those who are rheumatoid-factor positive are more likely to be affected in small joints such as fingers, hands and wrists.” 

There is no single test to diagnose juvenile idiopathic arthritis. A diagnosis will be made based on a child’s symptoms and by conducting a physical examination.

“The most important thing is whether or not a child can move the joint. You don’t have arthritis unless you have inflammation in the joint, and inflammation in the joint means it doesn’t move as well as it should,” Dr. Ferguson explains. “It’s often a matter of asking the patient, ‘Are you able to fully move your elbow or any affected joint?’ If the answer is ‘yes,’ then it is less likely an inflammatory problem. If I can feel, during my exam, that the joint doesn’t move well, we talk about lab tests and imaging tests, if needed.”

Lab tests and blood work can help distinguish one type of JIA from another. Imaging tests such as MRIs and bone scans can also show damage to the bones and joints. “MRIs are usually the most specific. X-rays can be done, but they aren’t as helpful,” Dr. Ferguson says. 

No matter what type of JIA your child has, the treatment plans are similar. They are as follows: 

• Nonsteroidal anti-inflammatory drugs (NSAIDs): These reduce symptoms, but do not stop the progression of the disease. The same types of NSAIDs (including aspirin, ibuprofen, naproxen, and naproxen sodium) that are used to treat arthritis in adults are also used in children.
• Disease-modifying antirheumatic drugs (DMARDs): If NSAIDs don’t relieve your child’s symptoms, his or her doctor may prescribe this type of medication. It slows JIA progression by suppressing the body’s immune and inflammatory response. There are many different types of DMARDs, but methotrexate is the one most commonly prescribed. It is taken as a pill or by injection.
• Corticosteroids: Steroids work quickly to reduce inflammation in the joint space. They are often used as the first treatment in severe disease so that long-term medication can be started. Prednisone is a corticosteroid that can be given by pill, injection, or intravenously.
• Biologic agents: This is a newer class of medications based on compounds made by living cells. One type is called tumor necrosis factor (TNF) inhibitors. These block TNF, a protein that occurs naturally in the body and causes inflammation. Other biologic agents block other inflammatory proteins, including interleukin-1 or T cells, which are part of the immune system and help fight infections.

“Basically, we first start with NSAIDs like ibuprofen or naproxen. If they’re not significantly beneficial, then we discuss what we call immunologic treatments like DMARDs and biologics,” Dr. Ferguson explains. 

The overall prognosis is “overwhelmingly good” for most children with JIA, Dr. Ferguson says. “And that’s because of the medicines. In the last 20 years, we have found more medications that focus well on the inflammatory parts of the immune system.”

With treatment, 50 to 70 percent of children with JIA go into remission. If caught and treated early, most children live normal, active lives. “It’s not always perfect because the disease can sometimes be tough to control, but we have a lot of treatment options and opportunities to move from one treatment to another. Our goal is to get the child feeling well and moving well,” Dr. Ferguson adds. 

Yale Medicine's pediatric rheumatologists specialize in treating juvenile idiopathic arthritis as well as other autoimmune diseases. There are many treatment options, ranging from anti-inflammatory medication to immune modulation. We also have procedural support (child life, sedation services) that allow us to perform steroid injections to affected joints for immediate relief and long-term benefit. 

Patients have access to our physicians,  nurse coordinator, and  many other services like physical therapy, social work, child life, and sedation services. 

Also helpful is a transition program for when children are ready to move into the care of an adult rheumatologist. “It’s a very clear, smooth process through which we make sure children are ready, instead of just handing them off when they turn 22,” Dr. Ferguson says. “We can work directly with the providers in the rheumatology department to ensure there is no interruption as young people move to the next stage of care.”

Our pediatric rheumatologists draw not only on their own expertise, but also collaborate with other experts from a national consortium called Childhood Arthritis Rheumatology Research Alliance (CARRA). Because JIA and related conditions are rare, it’s important to collect data from patients across the country so that we can understand the best treatment options for every child.