Rheumatoid arthritis (RA) in children is now known as juvenile idiopathic arthritis (JIA). There are several types of JIA, all of which cause pain and stiffness in the joints. JIA can last for months, years, or a lifetime.
Rheumatoid arthritis (RA) in children used to be called juvenile rheumatoid arthritis (JRA) but is now called juvenile idiopathic arthritis (JIA). The name changed because doctors wanted to make it clear that rheumatoid arthritis in children is a unique condition, different from rheumatoid arthritis in adults.
One of the most significant differences between RA and JIA is that children can outgrow their condition, while adults will always have it.
There are several subtypes of JIA, all of which cause pain, stiffness, and inflammation in the joints.
This article will explore the most common types of JIA in children, their symptoms, the diagnosis process, treatment, and complications.
JIA is the most common type of arthritis affecting children and teens. But the condition has
Oligoarticular juvenile idiopathic arthritis
This is the most common type of JIA. It initially affects 1 to 4 joints.
Doctors classify this type of JIA as persistent if symptoms continue for 6 months or longer. If symptoms worsen and 5 or more joints are affected after 6 months, doctors call it extended.
This type typically affects large joints like the ankles and knees. It may also involve eye inflammation called uveitis.
Polyarticular juvenile idiopathic arthritis-rheumatoid factor negative
Polyarticular juvenile idiopathic arthritis is the second most common type of JIA. It affects 5 or more joints during the first 6 months. Blood tests for rheumatoid factor, a marker of autoimmune disease, have negative results. Some children with this type develop chronic uveitis.
Polyarticular juvenile idiopathic arthritis-rheumatoid factor positive
In this type, 5 or more joints become affected within 6 months. But the child will have positive rheumatoid factor test results, which indicates an autoimmune disease. This type is very similar to adult RA and commonly affects preteen and teen girls.
Enthesitis-related juvenile idiopathic arthritis
Enthesitis is inflammation at the connection of a ligament or tendon to a bone. It commonly occurs in the knees, heels, and soles of the feet. This type combines flares of enthesitis and arthritis. Some children also develop acute anterior uveitis or inflammation in the front of the eye.
Psoriatic juvenile idiopathic arthritis
Children with this type typically develop psoriasis first, which is a condition affecting the skin. Sometimes signs of arthritis, like joint stiffness and pain, can develop before a psoriasis diagnosis is made. Other signs of this condition include pitted fingernails and swollen fingers and toes.
Systemic juvenile idiopathic arthritis
This type can affect the entire body and often begins with a fever and rash that comes and goes over the course of at least 2 weeks. The joints may become swollen and painful, but this may occur after the fever has cleared. In severe cases, inflammation forms in and near organs and the lining of organs like the heart and lungs.
This type includes those with symptoms that do not fit in with other types or that fit with more than one type.
Children may complain of a sore joint from time to time, but when the pain lasts for several weeks, it could be a sign of arthritis. Signs and symptoms to watch for include:
- joint pain or stiffness that worsens after waking or staying in one position for a while
- red, swollen, tender, or warm joints
- blurry vision, dry, gritty eyes
- loss of appetite
- high fever
To receive a JIA diagnosis, a child needs to be under the age of 16, have inflammation in one or more joints for at least 6 weeks, and have other conditions ruled out.
A doctor diagnoses childhood RA after conducting a
- MRI scan
- CT scan
If your doctor suspects arthritis, they may order laboratory blood tests. These might include:
- erythrocyte sedimentation rate and C-reactive protein tests to test for inflammation
- antinuclear antibody test, which returns positive if arthritis is present
- rheumatoid factor test, which may indicate polyarthritis
- HLA-B27 typing to test for enthesitis types of arthritis
- complete blood count levels
Before diagnosing JIA, a doctor will rule out other possible diagnoses like:
- childhood cancers
- bone diseases
- Lyme disease
Treatment depends on the type and severity of arthritis. Several options include:
An uncommon but serious complication called macrophage activation syndrome (MAS) due to immune system dysfunction can lead to a condition similar to sepsis. About 10% of children with JIA develop MAS.
If left untreated, RA can also lead to:
- digestive issues
- damage to the heart
- inflammation and scarring in the lungs
- late onset of puberty
- weight loss or gain
Rheumatoid arthritis is an autoimmune, inflammatory disease that occurs when the body begins to attack healthy cells and tissues. Because children’s RA differs from RA in adults, the name changed several years ago from juvenile rheumatoid arthritis (JRA) to juvenile idiopathic arthritis (JIA).
JIA has several subtypes, all of which cause pain, swelling, and stiffness in one or more joints, lasting 6 months or longer. There are effective treatments for JIA, including medications, surgery, and lifestyle modifications. Treatment depends on the disease type and severity.