What Is Juvenile Idiopathic Arthritis?

Juvenile idiopathic arthritis (JIA), formerly referred to as juvenile rheumatoid arthritis (JRA), is a group of autoimmune conditions that affects children ages 16 years and younger.

The cluster of disorders that make up JIA can impact multiple different joints in a child’s body at once and may also cause symptoms in other organs, like the eyes or skin. While kids frequently go into remission from JIA as they get older, the condition may cause adverse effects on a child’s bones as they mature and develop.

Types of Juvenile Idiopathic Arthritis

There are multiple versions of juvenile idiopathic arthritis, each with its own unique cluster of symptoms and targeted body regions. They include:

• Oligoarthritis: The most frequently seen version of JIA, this variety impacts four or fewer joints in a child’s body. Typically, oligoarthritis strikes larger joints like the ankles, elbows, or knees.
• Polyarthritis: In this subset of JIA, five or more joints are affected by inflammation. The impacted areas may be on both sides of the body, and both large and small joints (like the fingers or toes) can be involved.
• Systemic: Multiple joints and organs throughout the body are impacted. In addition to joint inflammation, a child’s skin and internal organs are commonly affected, leading to chronic fevers lasting up to several weeks and a widespread rash.
• Psoriatic arthritis: One or more joints in the body are targeted and a scaly rash develops on the eyelids, scalp, stomach, elbows, knees, or behind the ears. The wrist, knees, feet, hands, or elbows are the most commonly impacted joints in this subset of the disease.
• Enthesitis-related: This version of JIA is more common in boys and usually develops between the ages of 8 and 15. Sometimes referred to as spondyloarthritis, this condition targets the region where muscles, ligaments, and tendons connect to a child’s bones. Many different regions including the low back, chest, pelvis, hips, knees, fingers, feet, or even the digestive tract can be impacted.
• Undifferentiated: In some cases, a child’s symptoms do not fall perfectly into one of the subsets described above. In these situations, if one or more joint is impacted and inflammation is present, the condition is called undifferentiated juvenile idiopathic arthritis.

Juvenile Idiopathic Arthritis Symptoms

Because there are so many versions of JIA, the symptoms experienced by an individual can vary greatly.

In general, most varieties cause:

• Pain
• Stiffness to develop in one or more of a child’s joints

These symptoms are typically made worse by sitting or lying down for an extended period of time.

In addition, JIA may cause the joints to appear:

• Warm
• Red
• Swollen

This is because of the inflammation that is present.

Along with the joint issues, several other symptoms may also be present. A child may complain of:

• Being worn down or tired
• Losing their appetite

In some versions of this disease (psoriatic or systemic), a red or scaly rash can develop in one or more regions of the skin.

Systemic arthritis may also cause fevers of greater than 103 degrees Fahrenheit and a dry or gritty sensation in the eyes.

Causes

Juvenile idiopathic arthritis is an autoimmune disorder in which the child’s immune system “attacks” the protective lining that surrounds the joint (called the synovium) as though it is an invading microbe or virus. It is not completely understood why this response occurs, though several hypotheses have been formulated.

It is theorized that this gene is activated by exposure to an external virus or bacteria, leading to a faulty immune response. It is important to note that at this point, JIA does not appear to be caused by a vitamin deficiency or by certain types of foods or allergies.

Diagnosis

Unfortunately, it can be challenging to properly diagnose juvenile idiopathic arthritis, and there is no single test to rule the condition in or out. Instead, a thorough evaluation by a physician is necessary to assess the symptoms in a child’s joints and organs.

An X-ray may also be taken to assess the damage in one or several of a child’s joints, though it is important to remember that the adverse changes may not be evident early on in the disease process.

Other types of images, like a musculoskeletal ultrasound or an MRI, can also be used to measure joint erosion and tendon or ligament damage. In addition, a thorough eye exam by an ophthalmologist may be needed in systemic cases to assess any symptoms in this region. 

Treatment

The treatment options for JIA vary depending on which version of the disease a child has.

• In the case of systemic arthritis, joint inflammation and pain are typically treated with nonsteroidal anti-inflammatory drugs (NSAIDs). Higher doses of steroids and immunosuppressive medications may also be administered, though long-term use can cause significant side effects and should be approached cautiously. Typically, these drugs are initially given intravenously in an inpatient setting to monitor for adverse reactions.
• In rarer systemic cases, powerful medications called biologics may also be administered if the symptoms are not otherwise well controlled.
• The five other subsets of JIA are usually treated with NSAIDs and with another medication called methotrexate, which is given to control the faulty immune response. Both of these drugs are typically administered orally. In certain circumstances, oral steroid medications or biologics may be necessary to control the inflammation, though these drugs can cause significant side effects and need to be closely monitored by a physician.

Prognosis

Almost half of the kids who experience juvenile idiopathic arthritis go into remission and make a complete recovery. Unfortunately, this is not always the case.

In some situations, the symptoms of this disease can linger into adulthood and persistent rashes or fevers can continue. Other issues, such as progressive arthritis, weakening bone density (osteoporosis), and stunted bone growth may also occur.

In rare cases, JIA can even lead to long-term cardiac or kidney issues.

A Word From Verywell

The symptoms of juvenile idiopathic arthritis often emerge out of nowhere and can significantly impact the lives of kids 16 years and younger. Because of this, it can be a frustrating diagnosis to deal with.

Fortunately, in many cases, this condition eventually goes into remission and the symptoms subside. In the meantime, be sure to connect with a rheumatologist who is experienced in treating this complicated diagnosis. Doing so will ensure that unique symptoms are treated appropriately and increase the chances of returning to normal activities as soon as possible.