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Juvenile Idiopathic Arthritis (JIA)


Jay Mehta

, MD, Perelman School of Medicine at The University of Pennsylvania

Reviewed/Revised Apr 2022 | Modified Sep 2022
Topic Resources

Juvenile idiopathic arthritis is a group of related childhood diseases that begin by age 16 and involve persistent or recurring inflammation of the joints.

  • Certain forms of juvenile idiopathic arthritis may cause fever, rash, and lymph node swelling and may affect the heart.

  • Diagnosis is based on the child's symptoms and a physical examination because there is no single definitive laboratory test to diagnose the disease.

  • Children receive drugs to reduce inflammation and treat pain.

  • Physical therapy, including flexibility exercises, helps enhance joint movement.

Juvenile idiopathic arthritis (JIA) is a group of uncommon diseases characterized by inflammation of joints (arthritis). JIA may also affect other organs or connective tissue. Although most children who have JIA have a disease that is different than adult rheumatoid arthritis Rheumatoid Arthritis (RA) Rheumatoid arthritis is an inflammatory arthritis in which joints, usually including those of the hands and feet, are inflamed, resulting in swelling, pain, and often destruction of joints.... read more Rheumatoid Arthritis (RA) , a small percentage of children who have JIA do have a disease that is similar to adult rheumatoid arthritis.

The cause of JIA is unknown. Although JIA is not considered a hereditary disorder, hereditary factors may increase a child's chance of developing it. JIA is not due to an infection as some kinds of arthritis are.

Classification of JIA

There are several forms of JIA. Although each form has different characteristics, they share similar features. The form is determined by results of a doctor's examination and laboratory tests. Forms include the following:

  • Oligoarticular JIA

  • Polyarticular JIA (rheumatoid factor negative or positive)

  • Enthesitis-related arthritis

  • Psoriatic JIA

  • Undifferentiated JIA

  • Systemic JIA

Children may have one form when they are first diagnosed but sometimes develop a different form during the course of their illness.

Oligoarticular JIA is the most common form and usually affects young girls. In this form, four or fewer ("oligo" means "few") joints are affected during the first 6 months of the disease. The knee is the most frequently affected joint.

Polyarticular JIA is the second most common form and begins in late childhood. In this form, five or more ("poly" means "many") joints are affected. This form is divided into two types: rheumatoid factor negative and rheumatoid factor positive. Rheumatoid factor is an antibody in the blood. High levels of rheumatoid factor can occur in people who have rheumatoid arthritis Rheumatoid Arthritis (RA) Rheumatoid arthritis is an inflammatory arthritis in which joints, usually including those of the hands and feet, are inflamed, resulting in swelling, pain, and often destruction of joints.... read more Rheumatoid Arthritis (RA) but can also occur in people who have other autoimmune disorders Overview of Autoimmune Disorders of Connective Tissue In an autoimmune disorder, antibodies or cells produced by the body attack the body’s own tissues. Many autoimmune disorders affect connective tissue and a variety of organs. Connective tissue... read more (for example, systemic lupus erythematosus Systemic Lupus Erythematosus (SLE) Systemic lupus erythematosus is a chronic autoimmune inflammatory connective tissue disorder that can involve joints, kidneys, skin, mucous membranes, and blood vessel walls. Problems in the... read more Systemic Lupus Erythematosus (SLE) , polymyositis Autoimmune Myositis Autoimmune myositis causes inflammation and weakness in the muscles (polymyositis) or in the skin and muscles (dermatomyositis). Muscle damage may cause muscle pain and muscle weakness may cause... read more Autoimmune Myositis , or systemic sclerosis Systemic Sclerosis Systemic sclerosis is a rare, chronic autoimmune connective tissue disorder characterized by degenerative changes and scarring in the skin, joints, and internal organs and by blood vessel abnormalities... read more Systemic Sclerosis ).

Children who are rheumatoid factor positive have the rheumatoid factor antibody in their blood. The rheumatoid factor-positive type of JIA typically occurs in adolescent girls and is the same as adult rheumatoid arthritis. In both types, arthritis can affect the same joint on both sides of the body (for example, both knees or both hands) and frequently affects the small joints of the hands and feet.

Enthesitis-related arthritis involves arthritis and enthesitis (painful inflammation in areas where tendons and ligaments attach to bone). The arthritis often affects joints on only one side of the lower part of the body (such as the hip, knee, ankle, and foot). It is more common among older boys, and they may also develop arthritis in their lower spine.

Psoriatic JIA typically occurs in young girls but also occurs in older males and females (who are equally affected). Affected people may have the skin disease psoriasis Psoriasis Psoriasis is a chronic, recurring disease that causes one or more raised, red patches that have silvery scales and a distinct border between the patch and normal skin. A problem with the immune... read more Psoriasis or a family history of psoriasis in a parent or sibling.

Undifferentiated JIA is diagnosed when children do not meet criteria for any one form or meet criteria for more than one.

Systemic JIA (Still disease) involves arthritis along with symptoms outside of the joints, including fever, rash, lymph node swelling, and inflammation around the heart and lungs.

Symptoms of JIA

Juvenile idiopathic arthritis (JIA) causes symptoms in the joints and sometimes the eyes, skin, or both.

Joint symptoms occur with any form of JIA. The joints may be stiff when children awaken. Joints often become swollen and warm. Later, joints may become painful, but the pain may be milder than expected given the amount of swelling. Pain may become worse when the joint is moved. Children may be reluctant to walk or may limp. Joint pain persists for years if untreated. However, some children do not have any pain.

Enthesitis may cause tenderness of the pelvis, hip bone, spine, kneecap, the shin just below the knee, the Achilles tendon, and the sole of the foot.

Eye inflammation can occur with any form of JIA but is most common in oligoarticular JIA and very rare in rheumatoid factor-positive polyarticular JIA and systemic JIA. Inflammation typically involves the iris of the eye (iridocyclitis). Iridocyclitis in JIA usually does not cause symptoms (there is no pain or redness) but sometimes causes blurring of vision and irregular pupils. However, untreated iridocyclitis can lead to scarring, cataracts, glaucoma, and permanent loss of vision. Rarely, children with enthesitis-related arthritis have eye redness and pain and sensitivity to light.

Skin abnormalities occur mainly in psoriatic JIA and systemic JIA. Children with psoriatic JIA may have rough, psoriasis-like patches on their skin, swollen fingers and toes, and pitted nails. Children with systemic JIA sometimes develop a short-lived rash made up of flat, pink-colored or salmon-colored patches with clear centers—mainly on the trunk and the upper part of the legs or arms. The rash appears for hours at a time (often in the evening with fever) and does not always appear in the same spot.

Systemic JIA causes fever and inflammation at sites other than the joints. Children with systemic JIA typically develop a high fever and rash that frequently appear before joint pain and swelling. The fever comes and goes, usually for at least 2 weeks. The temperature is usually highest in the afternoon or evening (often 103° F [39° C] or higher) and then returns rapidly to normal. A child with fever may feel tired and irritable. The liver, spleen, and lymph nodes may enlarge. Sometimes inflammation develops in the membranes surrounding the heart (pericarditis) or in the membranes that cover the lungs (pleuritis) or inside the lungs, causing chest pain. This inflammation may cause fluid to accumulate around the heart, lungs, or other organs.

Complications of JIA

Any type of JIA can interfere with physical growth. Joint deformities may develop if untreated. When JIA interferes with growth of the jaw, a small chin (micrognathia) can result. Long-standing (chronic) joint inflammation can eventually cause deformities of or permanent damage to the affected joint.

Diagnosis of JIA

  • A doctor's evaluation

  • Blood tests

A doctor diagnoses JIA based on the child's symptoms and the results of a physical examination.

There is no single, definitive laboratory test for JIA, but some blood tests are helpful in distinguishing one form from another. Blood is tested for a full blood count, rheumatoid factor, antinuclear antibodies, anti-cyclic citrullinated peptide antibodies, and a certain antigen called HLA-B27, some of which are present in some people with rheumatoid arthritis and related autoimmune diseases.

The results of these tests can help doctors distinguish one form of JIA from another. However, most children with JIA do not have rheumatoid factor and most do not have antinuclear antibodies in their blood. Other blood tests, such as ferritin, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR), might also be done. Increased levels of CRP and ESR indicate inflammation.

Children with JIA who have antinuclear antibodies in their blood are at a higher risk of developing iridocyclitis. Children must be examined several times a year by an eye specialist (an ophthalmologist) for iridocyclitis regardless of whether symptoms are present because iridocyclitis may not cause any symptoms even though it is already causing eye inflammation. Children who have oligoarticular JIA or polyarticular JIA and who have antinuclear antibodies in their blood should have an eye examination every 3 months. Children who have oligoarticular or polyarticular JIA but who do not have antinuclear antibodies in their blood should have an eye examination every 6 months. Children who have systemic JIA should have an eye examination once a year.

X-rays may be taken to look for characteristic changes in the bones or joints.

Prognosis for JIA

With treatment, 50 to 70% of children have symptom-free periods (remissions). Children who have rheumatoid factor-positive polyarticular JIA have a less favorable prognosis. With early treatment, most children function normally.

Treatment of JIA

  • Disease-modifying antirheumatic drugs (DMARDs)

  • Sometimes corticosteroids

  • Sometimes nonsteroidal anti-inflammatory drugs (NSAIDs) for symptom relief

DMARDs can slow the progression of JIA and have dramatically improved outcomes. Examples of these drugs include methotrexate; etanercept, adalimumab, and infliximab (which block tumor necrosis factor-alpha, a protein involved in inflammation); anakinra and canakinumab (which block interleukin-1, a protein involved in inflammation); tocilizumab (which blocks interleukin-6); tofacitinib (which is a Janus kinase inhibitor); and abatacept. Sulfasalazine, another DMARD, is given occasionally, especially to children who have arthritis of the lower spine.

Methotrexate is given to children who have the oligoarticular, psoriatic, or polyarticular form of JIA. Side effects of methotrexate include a decrease in production of white blood cells, red blood cells, and platelets (bone marrow depression) and liver toxicity, so children taking this drug require regular blood tests.

Tocilizumab is given to children who have polyarticular or systemic JIA. Abatacept and tofacitinib are also used for the treatment of systemic JIA and polyarticular JIA. Anakinra and canakinumab are particularly effective for systemic JIA.

Doctors may inject corticosteroids directly into the affected joint or joints. Doctors try to avoid using systemic corticosteroids (such as prednisone given by mouth), but these drugs may be required for children with severe systemic JIA. When corticosteroids are necessary, the lowest possible dose is used to decrease the chance of long-term complications such as slowed growth, osteoporosis Osteoporosis Osteoporosis is a condition in which a decrease in the density of bones weakens the bones, making breaks (fractures) likely. Aging, estrogen deficiency, low vitamin D or calcium intake, and... read more Osteoporosis (brittle bones), cataracts, and osteonecrosis Osteonecrosis Osteonecrosis is the death of a segment of bone caused by an impaired blood supply. Osteonecrosis is most commonly caused by an injury but can also occur without an injury. Typical symptoms... read more (death of bone tissue).

Iridocyclitis is initially treated with corticosteroid eye drops, which suppress inflammation. If this treatment is not enough, methotrexate is frequently used and, if needed, a drug that blocks the effects of tumor necrosis factor. Eye drops that widen (dilate) the pupil also help prevent permanent eye damage. Eye surgery may be needed if the eye has been damaged.

Typically, nonsteroidal anti-inflammatory drugs Nonsteroidal Anti-Inflammatory Drugs Pain relievers (analgesics) are the main drugs used to treat pain. Doctors choose a pain reliever based on the type and duration of pain and on the drug's likely benefits and risks. Most pain... read more (NSAIDs) are given to reduce symptoms and are most useful for enthesitis-related arthritis. However, although NSAIDs help relieve symptoms, they do not stop the progression of joint disease.

More Information

The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

  • The Arthritis Foundation: Juvenile Arthritis: Comprehensive information on various types of arthritis in children, including JIA, and information regarding living with a juvenile arthritis and transitioning from pediatric care to adult care

Drugs Mentioned In This Article

Generic Name Select Brand Names
Jylamvo, Otrexup, Rasuvo, RediTrex, Rheumatrex, Trexall, Xatmep
Xeljanz, Xeljanz Oral, Xeljanz XR
Orencia, Orencia ClickJect
Azulfidine, Azulfidine En-Tabs, Sulfazine , Sulfazine EC
Deltasone, Predone, RAYOS, Sterapred, Sterapred DS
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