Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis is the most common type of arthritis affecting children, causing joint pain, swelling, and stiffness that can last for months, years, or even a lifetime. While the exact cause remains unknown, modern treatments can help children manage their symptoms and live full, active lives.

Table of contents

• What is juvenile idiopathic arthritis?
• Types of juvenile idiopathic arthritis
• Signs and symptoms
• Causes and risk factors
• How is it diagnosed?
• Treatment options
• Living with juvenile idiopathic arthritis
• Outlook and prognosis

What is juvenile idiopathic arthritis?

Juvenile idiopathic arthritis (JIA), formerly known as juvenile rheumatoid arthritis, is the most common chronic rheumatic disease in children^[1]. It affects children under the age of 16 and causes persistent joint pain, swelling, and stiffness lasting for at least six weeks^[1][4].

juvenile rheumatoid arthritis, juvenile chronic arthritis, JRA, JCA

The word “idiopathic” means unknown, and researchers aren’t sure why children develop JIA^[2]. It is an autoimmune disease, which means the body’s immune system, which normally fights germs and viruses, mistakenly attacks the body’s own healthy cells and tissues^[2][3]. In JIA, the immune system targets the synovium, the tissue that lines the inside of the joint, and the fluid within the joint. This causes the synovium to produce extra fluid, which leads to swelling, pain, and joint stiffness^[3].

This immune response and related inflammation can affect nearby tissues and eventually damage cartilage and bone. The inflammation can also affect other areas of a child’s body, especially their eyes^[3]. Left untreated, JIA can interfere with a child’s normal growth and development^[3].

JIA affects approximately 1 in 1,000 children in the United States, totaling about 300,000 children^[3]. It is most common in Caucasian children, affecting 8.3 out of every 100,000, and typically begins in children aged 2 to 4 years. The condition affects girls more often than boys^[18].

• Joints (knees, ankles, elbows, wrists, hands, feet)
• Eyes (uvea)
• Skin
• Heart
• Liver
• Spleen
• Lymph nodes
• Spine

Types of juvenile idiopathic arthritis

JIA is not a single disease but rather a group of different conditions. According to the International League of Associations for Rheumatology, there are seven main categories of JIA, each with distinct characteristics^[4]. Understanding which type a child has helps doctors determine the best treatment approach.

Oligoarticular JIA

This is the most common form of JIA, affecting about 50 percent of children with the condition^[3][15]. Oligoarticular means it affects four or fewer joints, typically large joints such as the knees, ankles, and elbows^[2][3]. This type most often begins in the toddler years and is more common in females^[3]. Many children outgrow this type by adulthood, though in some children, it can involve more joints over time^[3].

Children with oligoarticular JIA are at increased risk for uveitis, an inflammation of the middle layer of the eye. This eye inflammation may not cause obvious symptoms like redness or pain, but without treatment can harm vision^[3][5]. If the disease remains limited to four or fewer joints after six months, it is called “persistent” oligoarticular JIA. If more joints become affected after six months, it is called “extended” oligoarticular JIA^[8].

Polyarticular JIA

This type affects five or more joints, often the same joints on both sides of a child’s body, and accounts for about 20 to 40 percent of JIA cases^[2][3]. Polyarticular JIA can affect large joints and smaller joints, like those in the hands and feet, as well as the neck and jaw joints^[3]. The peak ages of onset are the toddler years and adolescent years, and it’s more common in females^[3].

This type is further divided based on whether rheumatoid factor (RF), an antibody found in the blood, is present. RF-positive polyarticular JIA is most common in adolescent girls and can have symptoms similar to adult rheumatoid arthritis^[8].

Systemic JIA

Sometimes called juvenile Still’s disease, systemic JIA occurs in about 10 to 20 percent of children with JIA^[3]. A systemic illness is one that may affect a child’s entire body or many body systems. Besides arthritis, systemic JIA usually causes a persistent high fever that spikes to 103°F or higher and lasts at least two weeks, along with a rash^[2][3]. The rash is often salmon-colored and most commonly appears on the trunk, arms, and legs when fever spikes^[3].

This type can affect internal organs including the heart, liver, spleen, and lymph nodes^[1][3]. It rarely affects the eyes and occurs equally in males and females^[3].

Psoriatic JIA

This type occurs when a child has both arthritis and psoriasis, a skin condition that causes thick, red patches or skin lesions covered with a silvery-white buildup of dead skin cells^[3]. Psoriatic arthritis can also be diagnosed even if a child doesn’t have psoriasis but has other features like a swollen finger or toe, certain nail changes, or a first-degree relative with psoriasis^[3]. It may affect one or more joints, often the wrists, knees, ankles, fingers, or toes^[2].

Enthesitis-related arthritis

Also known as juvenile spondyloarthritis or axial spondyloarthritis, this type affects a child’s spine, hips, and entheses, the points where tendons and ligaments attach to bones^[3][8]. A child’s eyes may also become painful or red. This type occurs mainly in males over the age of 7^[3].

Undifferentiated arthritis

This category is used when a child’s symptoms don’t meet criteria for any of the other types, or when symptoms meet criteria for more than one type^[6].

Signs and symptoms

The symptoms of JIA vary depending on the type a child has, but all types share the clinical feature of persistent swelling of the affected joints^[7]. Any joint can be affected, but large joints such as the knee and ankle are most commonly involved^[7].

The most common signs and symptoms include^[1][2]:

• Joint pain or stiffness, which may get worse after waking up or staying in one position too long
• Red, swollen, tender, or warm joints
• Joint swelling, often first noticed in larger joints such as the knee
• Limping, especially first thing in the morning or after a nap
• Appearing clumsier than usual, particularly in the morning or after naps
• Feeling very tired or rundown (fatigue)

While your child might not complain of joint pain, you may notice changes in how they move^[1]. Joint pain is an important symptom, although swelling may be difficult to detect clinically, especially for joints such as those of the spine, sacroiliac joints, shoulder, hip, and jaw^[7].

Additional symptoms that may occur in some types include^[1][2]:

• High fever (103°F or higher) that lasts at least two weeks
• Rash, often worse in the evenings
• Blurry vision or dry, gritty eyes
• Appetite loss
• Swollen lymph nodes

Involvement of small joints of the hands and feet is more likely when many joints are affected^[7]. Some children may experience symptoms for only a few months, while others have symptoms for many years or throughout their lives^[1].

Eye complications

JIA can cause inflammation inside the eye, which doctors call iritis or uveitis^[5]. JIA is the most common cause of uveitis in children. Unlike other types of eye inflammation, the inflammation from JIA does not usually cause an eye to be red or painful, but the swelling in the eye can harm vision if it is not treated^[5].

Without treatment, eye inflammation can cause^[5]:

• High eye pressure (glaucoma)
• Cloudy spots in the lenses of the eyes (cataracts)
• Calcium deposits in the cornea (band keratopathy)
• Scarring of the pupil
• Swelling in the retina
• Swelling of the optic nerve

All of these problems can cause very blurry vision and even blindness^[5]. This is why regular eye check-ups with an ophthalmologist are essential for children with JIA.

Causes and risk factors

The exact cause and trigger of JIA remain unclear^[4]. There is no evidence that foods, toxins, allergies, or lack of vitamins cause the disease^[2]. Researchers believe that abnormal immune responses triggered by interactions between environmental factors in a genetically susceptible individual are likely responsible^[4].

Children with JIA are believed to have certain genes that are activated by a virus, bacteria, or other external factors^[1]. Based on familial studies and the concordance rate of 25 to 40 percent in identical twins, genetic factors play a significant role^[4]. Specific HLA alleles (human leukocyte antigen variations) and non-HLA genes may make certain children vulnerable to particular JIA subtypes^[4].

Some environmental factors such as antibiotic exposure and C-section deliveries are potential risks, while breastfeeding and having household siblings may be protective^[4]. The roles of microorganisms such as Parvovirus B19, Epstein-Barr virus, and streptococcal infections remain inconclusive^[4].

How is it diagnosed?

Diagnosis of JIA can be difficult because joint pain can be caused by many different types of problems^[9]. A definitive diagnostic test for JIA is lacking, and diagnosis is made clinically by a combination of laboratory and clinical factors^[7]. No single test can confirm a diagnosis, but tests can help rule out other conditions that produce similar signs and symptoms^[9].

To diagnose JIA, doctors^[20]:

• Ask about symptoms and their duration
• Perform a physical examination
• Ask whether other family members have had similar problems
• Order blood tests
• Do X-rays or other imaging studies to look inside the joints

The diagnosis requires that the arthritis begins before age 16 years and lasts for at least six weeks^[4][8].

Blood tests

Some of the most common blood tests for suspected cases include^[9]:

• Erythrocyte sedimentation rate (ESR): Measures the speed at which red blood cells settle to the bottom of a tube of blood. An elevated rate can indicate inflammation.
• C-reactive protein: Measures levels of general inflammation in the body.
• Antinuclear antibody: Proteins commonly produced by the immune systems of people with certain autoimmune diseases. They are a marker for an increased chance of eye inflammation.
• Rheumatoid factor: An antibody occasionally found in children with JIA that may mean there’s a higher risk of damage from arthritis.
• Cyclic citrullinated peptide (CCP): Another antibody that may be found and can indicate a higher risk of damage.

In many children with JIA, no significant abnormality will be found in these blood tests^[9].

Imaging tests

X-rays or magnetic resonance imaging may be taken to exclude other conditions, such as fractures, tumors, infection, or congenital defects^[9]. Imaging may also be used after diagnosis to monitor bone development and to detect joint damage.

Sometimes, an orthopedic surgeon takes samples of joint fluid or synovium (the lining of the joints) for testing in the lab^[20].

Treatment options

The goals of treatment for JIA include suppression of inflammation with achievement of remission, relief of pain, maintenance of function, and minimizing toxicity^[11]. Treatment focuses on controlling pain and inflammation, improving function, and preventing damage^[1]. Starting the right treatment early is important to reduce inflammation, relieve pain and stiffness, prevent joint and organ damage, maintain movement in the joint, achieve remission, and help the child grow and participate in activities like school and sports^[10].

Treatment can significantly improve a child’s overall quality of life^[3]. Many therapies can result in either permanent remission, meaning the disease is no longer active (with the use of medication), or quiescence, meaning there are no symptoms (after finishing the medication course)^[8].

Medications

Medicines are the most important part of treatment for JIA. Without appropriate medication, the disease continues to cause irreversible damage to joints and possibly organs^[10]. Children may take some or all of the following:

Nonsteroidal anti-inflammatory drugs (NSAIDs): NSAIDs are often the first treatment doctors recommend^[10]. Some NSAIDs are available over the counter, while others require a doctor’s prescription. Medicines like ibuprofen (Advil, Motrin) and naproxen (Naprosyn) reduce inflammation and relieve pain and stiffness. NSAIDs still have a role in mild disease but shouldn’t be used long-term because of possible side effects like gastrointestinal problems and bruising^[10][11].

Corticosteroids: Injecting corticosteroids (steroids) directly into the affected joints quickly reduces inflammation and relieves pain^[10]. Intra-articular steroid injections continue to be used most commonly in patients with oligoarticular JIA^[11]. Doctors prescribe steroid pills for children at the lowest dose and for the shortest time possible to control symptoms. Taking oral steroids long-term can slow a child’s growth and cause side effects like weight gain, weak bones, and an increased risk for infections^[10].

Disease-modifying antirheumatic drugs (DMARDs): If many joints are involved or steroids and NSAIDs aren’t enough to calm inflammation, the doctor might add or switch to DMARDs^[10]. Methotrexate has demonstrated efficacy and safety and is commonly used; however, in many patients, the disease remains active despite this treatment^[11]. These medicines work more slowly than NSAIDs but can prevent joint damage.

Biologic agents: Important discoveries over the past 10 to 15 years have led to more targeted treatments for children with JIA^[11]. Children who remain active despite DMARD treatment now receive more targeted treatment including^[11]:

• Tumor necrosis factor alpha (TNFα) inhibitors
• Interleukin-1 blockade
• Interleukin-6 blockade
• Selective costimulation modulators
• Selective B-cell blockade

The biologic targeted therapies have changed the strategy in which doctors treat children with JIA; however, there remains much to be learned about the long-term effects and safety of these medicines^[11].

Physical therapy and other non-drug treatments

Physical and occupational therapy play important roles in managing JIA. A physical therapist can help with pain management, range of motion, muscle strengthening, and activities of daily living^[13]. Physical therapy and exercise help maintain joint mobility, strengthen muscles, and improve overall fitness^[22].

Generally, short rest breaks are better than long periods in bed^[19]. Finding a good balance with rest and exercise is important for children with JIA^[19]. When joints are inflamed, they are more prone to injury, so during these times, high impact activities such as running and jumping are not recommended. However, when a child is in remission (a period of no disease activity), regular physical activity is recommended to maintain cardiovascular health and bone and muscle strength^[17].

Treatment of uveitis

There are different medicines to help calm down the immune system and help the inflammation in the eye^[5]. These include:

• Steroid eye drops
• Other eye drops to make the pupil larger, which helps with eye pain and scarring
• Steroids by mouth (pills or liquid)
• Steroids as an injection around the eye
• Other medicines by mouth or injected into the body to calm the immune system

Surgery may be needed for some eye problems from uveitis^[5]. The uveitis can come back and may not cause eye redness or pain, which is why regular eye check-ups are so important^[5].

Multidisciplinary care

JIA is best treated with a team of doctors^[5]. This team typically includes:

• A primary care doctor
• A rheumatologist (arthritis doctor)
• An ophthalmologist (eye doctor)
• A physical therapist
• An orthopedic surgeon (bone and joint doctor) when needed

A multidisciplinary team approach to management is important, and the role of allied health professionals in the management of JIA has evolved in importance^[11].

Living with juvenile idiopathic arthritis

Having a child diagnosed with JIA can be overwhelming for parents. There is much to know, learn, and become acquainted with, but parents don’t have to know everything all at once^[17]. The relationship with a pediatric rheumatologist will not only provide answers and guidance but will also equip parents to be the best advocates and care providers for their child^[17].

Tips for parents

Here are practical tips for parents of children with JIA^[17][19]:

1. Organize medications: Many parents find using a pill box to organize daily medications minimizes the chances of forgetting or confusing medications. Identify one day of the week to plan out all medications for the upcoming week.
2. Write down questions before appointments: Keep questions in a handy notebook or in the “Notes” app on your phone to prevent forgetting them during the doctor’s visit.
3. Keep all medical appointments: These appointments are an important part of the care plan. When you can’t make an appointment, reschedule as soon as possible.
4. Observe your child for changes: Watch for limping, increased fatigue, moving more slowly in the morning (morning stiffness), decreased appetite, or swollen joints. These symptoms may be the first signs of a disease flare, even if your child says they “feel fine.” Alert the pediatric rheumatologist of any changes.
5. Educate teachers: Inform your child’s teachers about their JIA diagnosis. Children may require special accommodations such as a notetaker, extra time on tests, or accommodations for joint protection.
6. Discuss sports participation: Always discuss sports participation with the pediatric rheumatologist during regular appointments.
7. Be aware of vaccination guidelines: Some vaccinations, specifically live vaccines, are not compatible with specific medications used to treat JIA. Make sure your child is up to date on vaccinations before starting new medications.
8. Discuss medication side effects: Children will react differently to medications. Talk with the pediatric rheumatologist about any side effects.
9. Support a healthy lifestyle: It’s important that children have a balanced diet full of whole grains, lean protein, fruits, and vegetables. Children also need adequate sleep, which can range from nine to 13 hours depending on their age.
10. Stay positive: Keep a positive mindset and help your child understand that they are supported. Help answer any questions they have about JIA.

School and activities

Work with your child’s school and school health care provider to educate them on your child’s needs and how to best support them if they are experiencing pain^[17]. Running, leaping, climbing, and any other form of movement or play come naturally to children, but joint inflammation and stiffness can make these activities painful^[8]. With proper treatment and support, many children with JIA can participate in regular activities.

Outlook and prognosis

The prognosis for children with JIA has improved dramatically over recent decades, particularly with the introduction of biological therapies and a shift towards more aggressive treatment strategies^[7]. JIA treatment aims for normal physical and psychosocial functioning, which is an achievable goal for some children with this condition^[7].

Some children may experience symptoms for only a few months, while others have symptoms for many years^[1]. JIA is characterized by periods of remission and flare^[13]. Treatments can help with symptoms so children with JIA can live a full and active life. The symptoms can go away for a time (called remission), and in some children, the condition goes away permanently^[20].

Contemporary therapeutic goals include early achievement of disease control, sparing use of glucocorticoids, and the prevention of disease-related and treatment-related morbidity^[16]. The goal is for children to be symptom-free, and with many medications, this is possible^[8].

The American College of Rheumatology criteria for complete remission include^[13]:

• No inflammatory joint pain
• No morning stiffness
• No fatigue
• No synovitis (joint inflammation)
• No progression of damage on X-rays
• No elevation of inflammatory markers in blood tests

There is currently increasing interest in establishing the optimal time and modality for discontinuation of treatment in children with JIA who achieve sustained clinical remission^[16].