Juvenile idiopathic arthritis (JIA) is the most common type of arthritis in kids and teens. It typically causes joint pain and inflammation in the hands, knees, ankles, elbows and/or wrists. However, it can also affect other body parts. JIA was previously called juvenile rheumatoid arthritis (JRA), but the name was changed because JIA is not a kid version of the adult disease. The term “juvenile arthritis” is used to describe all the joint conditions that affect kids and teens, including JIA.
Studies show that Black children with JIA were nearly twice as likely to have joint damage as their white counterparts.
The Arthritis Foundation states that JIA types are autoimmune or autoinflammatory diseases. That means the immune system, which is supposed to fight invaders like germs and viruses, gets confused and attacks the body’s cells and tissues. This causes the body to release inflammatory chemicals that attack the synovium (tissue lining around a joint). It produces fluid that cushions joints and helps them move smoothly. An inflamed synovium may make a joint feel painful or tender, look red or swollen or difficult to move.
The word “idiopathic” means unknown and is symbolic of researchers not knowing why kids develop JIA. Despite the uncertainty, researchers believe that kids have certain genes that are activated by a virus, bacteria or other external factors. However, there is no evidence that foods, toxins, allergies or lack of vitamins cause the disease.
Children can start off with one type of JIA and develop symptoms of another type later.
The most common symptoms of JIA include:
- Joint pain or stiffness; may get worse after waking up or staying in one position too long.
- Red, swollen, tender or warm joints
- Feeling very tired or rundown (fatigue)
- Blurry vision or dry, gritty eyes
- Appetite loss
- High fever
Symptoms that may be specific to the six types of JIA:
Oligoarthritis: Affects four or fewer joints, typically the large ones (knees, ankles, elbows). ost This is the most common subtype of JIA.
Polyarthritis: Affects five or more joints, often on both sides of the body (both knees, both wrists, etc.). Polyarthritis may affect large and small joints and affects about 25% of children with JIA.
Systemic: Affects the entire body (joints, skin and internal organs). Symptoms may include a high spiking fever (103°F or higher) that lasts at least two weeks and a rash. This subtype affects about 10% of children with JIA.
Psoriatic arthritis (PsA): Joint symptoms and a scaly rash behind the ears and/or on the eyelids, elbows, knees, belly button and scalp. Skin symptoms may occur before or after joint symptoms appear. PsA may affect one or more joints, often the wrists, knees, ankles, fingers or toes.
Enthesitis-related (spondyloarthritis): Affects where the muscles, ligaments or tendons attach to the bone (entheses). This subtype typically affects the hips, knees and feet, but may also affect the fingers, elbows, pelvis, chest, digestive tract (Crohn’s disease or ulcerative colitis) and lower back (ankylosing spondylitis). This type of arthritis is more common in boys and typically appears in children between the ages of eight and 15.
Undifferentiated: Undifferentiated means that your child’s symptoms may not match up perfectly with any of the subtypes, but inflammation is present.
JIA symptoms may also come and go. If your child experiences periods of lots of inflammation and worsening symptoms, they are called flares. A flare can last for days or months.
If JIA inflammation goes unchecked, it can damage the lining that covers the ends of bones in a joint (cartilage), and the bones themselves.
JIA can also cause the following complications:
- Eyes. Dryness, pain, redness, sensitivity to light and trouble seeing properly caused by uveitis (chronic eye inflammation). This complication is most common in children with oligoarthritis.
- Bones. Chronic inflammation and use of corticosteroids may cause growth delay in some children with JIA. Their bones may get thinner and break more easily (osteoporosis).
- Mouth/Jaw. Difficulty chewing, brushing or flossing. More than half of children with JIA have jaw involvement.
- Neck. Inflammation of the cervical spine can cause neck pain or stiffness. Swollen neck glands could also signal an infection for kids with SJIA or who are taking immunosuppressing drugs.
- Ankles/feet. Foot pain and difficulty walking is more common in children with polyarthritis and enthesitis-related arthritis.
- Skin. Symptoms can range from a faint salmon colored rash (SJIA) to a red, scaly rash (psoriatic arthritis).
- Lungs. Inflammation and scarring that can lead to shortness of breath and lung disease. May occur in SJIA.
- Heart. Inflammation may cause damage to the heart muscle. This may occur in children with SJIA.
- Digestive Tract. Abdominal pain and diarrhea is more common in children with spine arthritis or ankylosing spondylitis.
- Reproductive organs. Late onset of puberty. Certain drugs such as cyclophosphamide could potentially lead to fertility problems later.
- Weight loss or gain. Due to changes in appetite, jaw involvement or difficulty exercising. If your child is overweight, they may be putting extra stress on their joints.
Keeping your child’s inflammation under control and managing the disease can prevent damage and complications from these health effects.
According to the American College of Rheumatology (ACR), a child must have inflammation in one or more joints that lasts at least six weeks, be under 16 years old and have all other conditions ruled out before being diagnosed with JIA.
A pediatrician may be the first doctor to start figuring out what’s causing symptoms. It’s likely that parents will be referred to a rheumatologist (a doctor with specialized training in treating arthritis). Some rheumatologists only treat children, while others only treat adults and some of them treat both. A medical history, physical examination and blood tests will help doctors make the correct diagnosis.
Although there is no cure for JIA, your child may enter a period of remission (little or no disease activity or symptoms). Early aggressive treatment is key to getting the disease under control as quickly as possible.
Treatment for JIA varies depending on your child’s disease type and severity. A well-rounded plan includes medication, complementary therapies and healthy lifestyle habits.
No matter what treatments your child’s doctor prescribes, the ultimate goal will be to:
- Slow down or stop inflammation.
- Relieve symptoms, control pain and improve quality of life.
- Prevent joint and organ damage.
- Preserve joint function and mobility.
- Reduce long-term health effects.
- Achieve remission (little or no disease activity or symptoms).