Juvenile idiopathic arthritis (JIA), previously known as juvenile rheumatoid arthritis, is a type of joint inflammation that occurs in children and adolescents before the age of 16, causing joint pain, stiffness, and swelling for more than six weeks. The term, “idiopathic,” means of unknown cause, although juvenile idiopathic arthritis is thought to be an autoimmune disorder, affecting females more than males. Nearly 50% of children and adolescents will outgrow the disease; however, it can still cause lasting joint damage. There are several types of juvenile idiopathic arthritis, which are determined by their symptoms, the affected joints, lab tests, and family history, and which include the following: Systemic juvenile idiopathic arthritis – This type of juvenile idiopathic arthritis affects one or more joints, causing joint inflammation accompanied by a fever that lasts at least two weeks. In addition, systemic juvenile idiopathic arthritis may also be accompanied by a skin rash, or enlarged lymph nodes, lungs, liver, or spleen. Oligoarticular juvenile idiopathic arthritis (Oligoarthritis) – This type of juvenile idiopathic arthritis is the most common type (more than 50%) and occurs in four joints or less during the first six months of the disease and has two subtypes: 1) persistent oligoarthritis (four affected joints or less after six months); and 2) extended oligoarthritis (more than four affected joints after six months). Individuals with oligoarthritis have an increased risk of developing eye inflammation (uveitis or iridocyclitis). Rheumatoid factor positive polyarticular juvenile idiopathic arthritis (Polyarthritis) – This type of juvenile idiopathic arthritis affects more than five joints, usually the fingers or toes, during the first six months of the disease and is similar to adult rheumatoid arthritis, as patients with this type test positive for rheumatoid factor and may develop small bumps near joints (rheumatoid nodules). Rheumatoid factor negative polyarticular juvenile idiopathic arthritis (also called Polyarthritis) – This type of juvenile idiopathic arthritis affects five or more joints during the first six months of the disease; however, patients with this type test negative for rheumatoid factor. Psoriatic juvenile idiopathic arthritis – This type of juvenile idiopathic arthritis occurs alongside psoriasis, a skin disorder which is characterized by reddened skin plaques (patches) covered with white scales and which can also include nail abnormalities (pitting) and eye inflammation. Enthesitis-related juvenile idiopathic arthritis (Juvenile spondyloarthritis) – This type of juvenile idiopathic arthritis affects the areas where bone connects with tendons, ligaments, or other connective tissue, usually in the hips, knees, or feet, causing tenderness (enthesitis), along with joint inflammation, and may affect other areas of the body, such as the eyes (uveitis), and is more common in males than females. Reactive arthritis (Reiter’s syndrome) – This type of arthritis develops as a reaction to bacterial infections, such as shigella, salmonella, yersinia, or genitourinary chlamydial infection (sexually transmitted disease), and occurs abruptly, causing fever, joint pain and inflammation, painful urination, and eye infection (conjunctivitis). Juvenile systemic lupus erythematosus (Lupus) – This disease can cause joint inflammation in addition to inflammation in several other areas of the body. Undifferentiated arthritis – This type of juvenile idiopathic arthritis covers any type that does not fall into the above categories.

There are several alternative names for juvenile idiopathic arthritis, including arthritis, enthesitis-related juvenile idiopathic arthritis, juvenile chronic arthritis, JIA, juvenile spondyloarthritis, juvenile rheumatoid arthritis (JRA), juvenile RA, oligoarticular juvenile idiopathic arthritis, polyarthritis, psoriatic juvenile idiopathic arthritis, rheumatoid factor negative polyarticular juvenile idiopathic arthritis, rheumatoid factor positive polyarticular juvenile idiopathic arthritis, and systemic juvenile rheumatoid arthritis.

While the exact cause of juvenile idiopathic arthritis is unknown, researchers believe it is a genetic autoimmune disorder, which means that the body’s immune system attacks the normal joint linings (synovial membranes), causing inflammation, stiffness, pain and tenderness, eventually damaging cartilage and bone, usually after being triggered by a bacterial or viral infection. Since the ends of bones are the growth areas, damaged bones may develop abnormalities. Juvenile idiopathic arthritis may also have a genetic factor as mutations in the genes that make human leukocyte antigen (HLA antigen DR4) complex that helps the immune system produce certain proteins may also increase the risk of developing juvenile idiopathic arthritis. However, the majority of juvenile idiopathic arthritis cases occur in individuals with no family history of the disease.

Symptoms of juvenile idiopathic arthritis may vary by individual, affect a few joints or several joints, and may also cause symptoms in other areas of the body. The most common symptoms of juvenile idiopathic arthritis include stiff, swollen, painful joints, especially in the morning, that may last only a few months, or for a lifetime. Additional symptoms of juvenile idiopathic arthritis may include fatigue, decreased appetite, poor weight gain, stunted growth, irritability, clumsiness, limping, bent posture, rash, fever, swollen lymph nodes, joints that appear deformed, bone growth abnormalities (uneven leg lengths), small bumps around joints (rheumatoid nodules), chest pain, eye inflammation, or blurry vision. Juvenile idiopathic arthritis is further characterized by flare-ups followed by periods without any symptoms.

Treatments for juvenile idiopathic arthritis focus on relieving joint pain and swelling, increasing movement and strength, and preventing complications, and usually includes medications, physical therapy, exercise, adequate rest, healthy diet, and regular eye exams. Severe cases of juvenile idiopathic arthritis may require surgery. Medications –  Medications used for juvenile idiopathic arthritis include non-steroidal anti-inflammatory drugs (NSAIDs; ibuprofen ) and naproxen sodium (Aleve, Naprosyn, and others) or COX-2 inhibitors, such as celecoxib (Celebrex), all of which are used to reduce joint pain and inflammation; disease-modifying antirheumatic drugs (DMARDs; methotrexate ) to relieve joint pain and swelling when there is high risk of joint damage; biologic agents (tumor necrosis factor (TNF) blockers (etanercept ) and adalimumab (Humira) to reduce systemic inflammation and prevent joint damage; and other biologic agents to suppress the immune system, such as abatacept (Orencia), rituximab (Rituxan), anakinra (Kineret), canakinumab (Ilaris), infliximab (Remicade), and tocilizumab (Actemra); and corticosteroids, such prednisone, to control symptoms and other inflammation, such as pericarditis (inflammation of the heart lining). Other medications for juvenile idiopathic arthritis may include hydroxychloroquine (Plaquenil), sulfasalazine (Azulfidine), leflunomide (Arava), azathioprine (Imuran), cyclosporine (Neoral, Sandimmune), and thalidomide. Physical therapy may be recommended for juvenile idiopathic arthritis to maintain joint flexibility, range of motion, and muscle tone, in addition to the use of protective devices, such as joint supports or splints. Some children may need counseling to help deal with having a chronic illness, nutritional counseling, and regular eye exams. Very severe cases of juvenile idiopathic arthritis may require surgery to correct a joint abnormality caused by the disease.

There are several online, local, national, and international support groups for juvenile idiopathic arthritis, including the following: Arthritis Foundation - https://www.arthritis.org/juvenile-arthritis Arthritis Society - https://arthritis.ca/support-education/support-for-childhood-arthritis Juvenile Arthritis Association - http://www.juvenilearthritis.org/ Systemic Juvenile Idiopathic Arthritis Foundation - https://www.systemicjia.org/patient-resources/

The outcomes (prognosis) for juvenile idiopathic arthritic varies by individual; however, the disease is generally characterized by flare-ups followed by periods of no symptoms. Treatments can help control symptoms. While the disease eventually disappears in nearly 50% of children with juvenile idiopathic arthritis, some children may continue to have symptoms for several years. Children with juvenile idiopathic arthritis who experience severe symptoms may have permanent joint or bone damage and abnormalities, as well as stunted growth, or rarely—kidney, heart, or endocrine system disorders.

Possible complications of juvenile idiopathic arthritis can be serious, such as stunted growth and bone development, permanent joint damage, and eye inflammation (cataracts, glaucoma, iridocyclitis, uveitis, or blindness). Children with oliogoarthritis should have frequent eye examinations.

If your child experiences any of the symptoms of juvenile idiopathic arthritis, such as rash, fever, persistent joint pain, swelling, stiffness, limited motion, or limping for more than one week, make an appointment with their doctor as soon as possible.

There is currently no known method to prevent juvenile idiopathic arthritis.