Oligoarticular arthritis

Oligoarticular arthritis also called pauciarticular juvenile idiopathic arthritis, is the most common type of juvenile idiopathic arthritis or JIA in young people, affecting four joints or less, typically the large ones (knees, ankles, elbows), in the first six months of symptoms. Juvenile idiopathic arthritis or JIA is the most common type of arthritis in kids and teens. JIA typically causes joint pain and inflammation in the hands, knees, ankles, elbows and/or wrists. But, it may affect other body parts too. JIA used to be called juvenile rheumatoid arthritis (JRA), but the name changed because it is not a kid version of the adult disease. The term “juvenile arthritis” also known as pediatric rheumatic disease, is an umbrella term to describe the inflammatory and rheumatic diseases including JIA that develop in children under the age of 16, often begins in young children between 2 and 4 years of age.

Oligoarticular arthritis occurs in 50% to 60% of children and teenagers who have JIA or juvenile idiopathic arthritis. Oligoarticular arthritis is the most common type of JIA in children and teenagers constituting approximately 50 percent of cases of JIA. Oligoarticular arthritis affects up to four joints in the first six months of symptoms. There are two types of oligoarticular arthritis. These are oligoarticular-persistent arthritis and oligoarticular-extended arthritis ¹⁾.

1. Oligoarticular-persistent arthritis there is no additional joint involvement after the first six months of illness
2. Oligoarticular-extended arthritis there is involvement of additional joints after the first six months such that more than four joints are ultimately affected.

Approximately 50 percent of children with oligoarticular disease go on to have extended oligoarticular disease ²⁾.

Although no cure exists for oligoarticular arthritis, many therapies do that can be used to ease disease symptoms and improve quality of life. Physicians may prescribe steroids, or non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, to limit pain and inflammation. To treat uveitis, steroids in the form of eye drops may be applied directly to the eye. Disease-modifying anti-rheumatic drugs (DMARDs), available in tablet, liquid, or injectable forms, can be used to slow or stop arthritis progression.

Children with oligoarticular arthritis generally have reduced aerobic and anaerobic capacities. Both high- and low-impact exercise programs have been shown to improve their physical health without exacerbating the symptoms of arthritis.

Oigoarticular-persistent arthritis

About 75% of children with oligoarticular JIA have the oligoarticular-persistent arthritis type.

Oligoarticular-persistent arthritis is generally the mildest form of JIA.

• Oligoarticular-persistent arthritis affects more affects girls more often than boys.
• Oligoarticular-persistent arthritis usually begins before four years of age.
• It most often affects the large joints such as the knee, ankle, wrist, and/or elbow joints.
• No more than four joints inflamed after six months
• Usually have joints that work well
• Good chance of remission before adulthood
• Oligoarticular-persistent arthritis can be associated with an eye disease called uveitis, which affects up to 20% of young people with this type of JIA.

It is rare to have permanent joint damage with appropriate treatment of this type of JIA. Some young people with this type of JIA go into permanent remission a few years after their symptoms begin. For others, the disease may last into adulthood.

Oligoarticular-extended arthritis

About 25% of children with Oligoarticular JIA have the oligoarticular-extended arthritis type.

This type of JIA also affects four or fewer joints in the first six months after diagnosis. However, after six months or more, patients with oligoarticular-extended arthritis develop arthritis in five or more joints.

Here are a few facts about oligoarticular-extended arthritis:

• More common in girls than boys, is more likely to start between 1 and 12 years of age and affects five or more joints in the first six months.
• Approximately 20% to 30% of patients who start out with oligoarticular arthritis will develop extended arthritis at some point.
• Oligoarticular-extended arthritis can affect both large and small joints.
• Less chance of going into full remission than in the persistent oligoarticular type
• With good treatment, usually have joints that work well.

Oligoarticular arthritis causes

The cause and pathogenesis of juvenile idiopathic arthritis (JIA) are not completely understood. Juvenile idiopathic arthritis (JIA) 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 researchers aren’t sure why kids develop JIA. They believe kids with JIA have certain genes that are activated by a virus, bacteria or other external factors. But there is no evidence that foods, toxins, allergies or lack of vitamins cause the disease. The IL2RA/CD25 gene has been implicated as a JIA susceptibility locus, as has the VTCN1 gene ³⁾. Associations have been found between specific HLA alleles and clinical subtypes of JIA (eg, HLA-A(*)02:06 with susceptibility to JIA accompanied by uveitis, and HLA-DRB1(*)04:05 with polyarticular JIA, in a Japanese cohort) ⁴⁾.

A study by Ombrello ⁵⁾ examined the MHC locus in a large collection of systemic juvenile idiopathic arthritis patients and verified the relationship between the class II HLA region and systemic juvenile idiopathic arthritis, implicating adaptive immune molecules in the pathogenesis of the disease.

Humoral and cell-mediated immunity are involved in the pathogenesis of JIA. T lymphocytes have a central role, releasing proinflammatory cytokines (eg, tumor necrosis factor–alpha [TNF-α], interleukin [IL]-6, IL-1) and favoring a type-1 helper T-lymphocyte response. A disordered interaction between type 1 and type 2 T-helper cells has been postulated.

Studies of T-cell receptor expression confirm recruitment of T-lymphocytes specific for synovial nonself antigens. Evidence for abnormalities in the humoral immune system include the increased presence of autoantibodies (especially antinuclear antibodies), increased serum immunoglobulins, the presence of circulating immune complexes, and complement activation.

Chronic inflammation of synovium is characterized by B-lymphocyte infiltration and expansion. Macrophages and T-cell invasion are associated with the release of cytokines, which evoke synoviocyte proliferation. A study by Scola et al ⁶⁾ found synovium to contain messenger ribonucleic acid (mRNA) for vascular endothelial growth factor and angiopoietin 1, as well as for their receptors, suggesting that induction of angiogenesis by products of lymphocytic infiltration may be involved in persistence of disease.

Some pediatric rheumatologists view systemic-onset JIA as an autoinflammatory disorder, such as familial Mediterranean fever (FMF) or cryopyrin-associated periodic fever syndromes, rather than a subtype of JIA. This theory is supported by work demonstrating similar expression patterns of a phagocytic protein (S100A12) in systemic-onset JIA and familial Mediterranean fever, as well as the same marked responsiveness to IL-1 receptor antagonists ⁷⁾.

Familial Mediterranean fever is associated with mutations in the MEFV gene; these mutations are associated with activation of the IL-1b pathway, resulting in inflammation. A study by Ayaz et al ⁸⁾ found an increased frequency of MEFV mutations in Turkish children who were diagnosed with systemic JIA; this study has not been replicated in other populations.

In a nested case–control study of 153 children with juvenile arthritis and 1,530 matched controls, researchers found that exposure to antibiotics during childhood significantly increased the risk for developing JIA in a dose-dependent manner. Compared with those with no exposure, the odds ratio for developing JIA was 3.1 for children exposed to one or two courses of antibiotics, and for those exposed to three to five courses the odds ratio was 3.8 ⁹⁾. The association between antibiotic exposure and JIA was similar for different classes of antibiotics. No association was found between exposure to nonbacterial antimicrobial agents and JIA. Adjustment for the number and type of infections and age at antibiotic exposure did not change the associations significantly ¹⁰⁾.

Oligoarticular arthritis symptoms

Oligoarticular JIA most commonly affects larger joints, including the knees, ankles, wrists, elbows, and hips. But, especially in children with extended oligoarticular JIA, it can also affect finger and toe joints. Symptoms include limping and discomfort when standing and walking, pain and swelling in the joints that lasts for more than six weeks, and overall feelings of weakness, fatigue, and fever. Typically, the affected joints do not incur lasting damage, and most children grow out of the disease by adulthood.

Children with oligoarticular JIA, however, are at risk of a serious eye inflammation called uveitis, an inflammation of the middle layer of the eye (called the uvea, and includes the iris). If untreated, uveitis can damage vision and even cause blindness. About 20 percent of oligoarticular JIA patients will develop uveitis.

Uveitis may be difficult to identify because, in about 50 percent of all JIA-related cases, it does not cause distinct symptoms: redness or pain in the eye, blurred vision, or unusual light sensitivity. For this reason, children with oligoarticular JIA are strongly encouraged to undergo regular eye examinations with an ophthalmologist aware of their disease. Patients with positive antinuclear antibody test results, a test used to evaluate the presence of autoimmune disorders, are thought to be at highest risk of developing uveitis.

Oligoarticular arthritis diagnosis

According to American College of Rheumatology a child must have inflammation in one or more joints lasting 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. Others only treat adults. Some of them treat both. A medical history, physical examination and blood tests helps to make the correct diagnosis.

Medical history

The doctor will ask questions about the child’s health history, when symptoms started and how long they lasted. This helps rule out other causes like trauma or infection. The doctor will also ask about the family’s medical history.

Physical examination

The doctor will look for joint tenderness, swelling, warmth and painful or limited movement and test range of motion. Eyes and skin may also be checked.

Laboratory tests

The doctor may order blood tests that look for certain proteins and chemicals found in some people with arthritis. These tests include:

• Erythrocyte sedimentation rate (ESR, or “sed rate”) and C-reactive protein (CRP) tests: High ESR rates and CRP levels signal severe inflammation in the body.
• Antinuclear antibody (ANA) test: A positive ANA test is associated with many types of arthritis, but kids without JIA may also have a positive ANA.
• Rheumatoid factor (RF) test: May show up in children with polyarthritis. A positive rheumatoid factor may signal more serious disease.
• HLA-B27 typing (a genetic marker): The HLA-B27 gene is associated with enthesitis-related types of arthritis, such ankylosing spondylitis.
• Complete blood count (CBC): Raised levels of white blood cells and decreased levels of red blood cells is linked to certain types of arthritis.
• Imaging. The doctor may order imaging tests, such as X-rays, ultrasound and MRI or CT scans, to look for signs of joint damage.

Oligoarticular arthritis treatment

There is no cure for JIA but remission (little or no disease activity or symptoms) is possible. Early aggressive treatment is key to getting the disease under control as quickly as possible.

The goals of JIA treatment are 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).

Treatment for JIA varies depending on disease type and severity. A well-rounded plan includes medication, complementary therapies and healthy lifestyle habits.

Drugs that control disease activity

Disease-modifying antirheumatic drugs (DMARDs). These drugs work to modify the course of the disease. DMARDs relieve symptoms by suppressing the immune system so it doesn’t attack the joints.

• Traditional DMARDs. These have been used the longest and have a broad immune-suppressing effect. The most commonly-used drug for JIA is methotrexate. These medicines are available in pill or injection form.
• Biologics. These drugs target certain steps or chemicals in the inflammatory process and may work more quickly than traditional DMARDs. They are self-injected or given by infusion in a doctor’s office.

Drugs that relieve symptoms

Nonsteroidal anti-inflammatory drugs (NSAIDs) and analgesics (pain relievers). These drugs relieve pain but cannot reduce joint damage or change the course of JIA. These medications are available over-the-counter or by prescription.

Every child with JIA is different. The standard of care involves trying methotrexate first, but many doctors start with a biologic/DMARD combination to combat inflammation as quickly as possible. As doctors monitor the disease, drugs may be added or removed.

Exercise

Regular exercise helps ease joint stiffness and pain. Low-impact and joint-friendly activities like walking, swimming, biking and yoga are best, but kids with well-controlled disease can participate in just about any activity they wish, if their doctor or physical therapist approves.

Physical therapies and assistive devices

Physical and occupational therapy can improve a child’s quality of life by teaching them ways to stay active and how to perform daily tasks with ease. Children with JIA may also have trouble with balance and weaker motor skills, or the ability to move and coordinate large muscle groups. Participating in regular physical and occupational therapy can improve coordination and balance, among other things. Here are some other ways physical and occupational therapists can help a child with JIA:

• Teach and guide them through strengthening and flexibility exercises.
• Perform body manipulation.
• Prescribe assistive devices (e.g. braces, splints).

Self care and lifestyle changes

Healthy eating

While there is no special JIA diet, studies show that some foods help to curb inflammation. These include the foods found in the Mediterranean diet, i.e. fatty fish, fruits, vegetables, whole grains and extra virgin olive oil among others. Children with JIA should avoid or cut back on foods that can cause inflammation such as high-fat, sugary and processed foods.

Hot and Cold treatments

Heat treatments, such as heat pads or warm baths, work best for soothing stiff joints and tired muscles. Cold is best for acute pain. It can numb painful areas and reduce inflammation.

Mind-Body therapies

There are different ways to relax and stop focusing on pain. They include meditation, deep breathing and practicing visualization, or thinking about peaceful places or happy memories. Children with JIA may also benefit from certain distraction techniques to lessen pain, especially during shot time. These include listening to music, coloring or drawing, reading and being read to.

Massage and acupuncture can also help reduce pain and ease stress or anxiety. Acupuncture involves inserting fine needles into the body along special points to relieve pain. If there’s a fear of needles, acupressure, which uses firm pressure, may be used instead.

Balancing activity with rest

When JIA is active, and joints feel painful, swollen or stiff, it’s important to balance light activity with rest. Rest helps reduce inflammation and fatigue that can come with a flare. Taking breaks throughout the day protects joints and preserves energy.

Topical products

These creams, gels or stick-on patches can ease the pain in a joint or muscle. Some contain the same medicine that’s in a pill, and others use ingredients that irritate nerves to distract from pain.

Stress and Emotions

Children and teens with JIA are more likely to get depressed because they are living with a chronic disease. Having a strong support system of friends and family can provide emotional support during tough times. Children with JIA can make new friends dealing with similar struggles at various Arthritis Foundation events held throughout the year. Therapist and psychologists can also help kids with JA deal with tough emotions and teach positive coping strategies.

Supplements

The use of supplements is rarely studied in children. But some supplements that adults take may help children too. These include curcumin, a substance found in turmeric, and omega-3 fish oil supplements, which may help with joint pain and stiffness. Taking calcium and vitamin D can help build strong bones. Always discuss supplements and vitamins with a child’s doctor. Some may cause side effects and interact with other medications.

Surgery

Thanks to treatment advances, including biologics, many children will never need surgery. But for children whose disease couldn’t be controlled early enough, surgery can provide much needed relief and restore joint function.

Damaged parts of a joint are replaced with metal, ceramic or plastic prosthesis. Hip and knee replacements are most common, and many surgeries can be performed on an outpatient basis. There are other surgeries that can improve joint function and quality of life but require much less cutting than joint replacement. For example, with arthroscopy, a thin, lighted tube with a camera attached is inserted through a small incision. This helps the surgeon examine the child’s joints and perform procedures, such as removing a loose piece of cartilage. An orthopedic surgeon will evaluate and determine if surgery is the best option.