Juvenile idiopathic arthritis


 * This article does not deal with the more general topic of childhood arthritis.

Juvenile idiopathic arthritis (JIA), also known as juvenile rheumatoid arthritis (JRA), is the most common form of arthritis in children and adolescents. (Juvenile in this context refers to an onset before age 16, idiopathic refers to a condition with no defined cause, and arthritis is the inflammation of the synovium of a joint.)'''

JIA is a subset of arthritis seen in childhood, which may be transient and self-limited or chronic. It differs significantly from arthritis commonly seen in adults (osteoarthritis, rheumatoid arthritis), and other types of arthritis that can present in childhood which are chronic conditions (e.g. psoriatic arthritis and ankylosing spondylitis). It is an autoimmune disorder. The disease commonly occurs in children from the ages of 7 to 12, but it may occur in adolescents as old as 15 years of age, as well as in infants. JIA affects approximately 1 in 1,000 children in any given year, with about 1 in 10,000 having a more severe form.

Terminology
The terminology used is evolving, and each term has some limitations.

According to some sources, JIA replaces the term juvenile rheumatoid arthritis (JRA). Other sources still use the latter term.

JIA is sometimes referred to as juvenile chronic arthritis (JCA), a term that is not precise as JIA does not encompass all forms of chronic childhood arthritis.

A majority of cases are rheumatoid factor negative, which leads some to consider the "chronic" or "idiopathic" labels more appropriate. However, if a cause was determined, then "idiopathic" may no longer be appropriate (making JIA a diagnosis of exclusion), and if the course was self-limited, then "chronic" may no longer be appropriate.

Adding to the confusion, the term rheumatoid itself lacks a consistent, unambiguous definition.

MeSH uses "Juvenile Rheumatoid Arthritis" as the primary entry, and uses "chronic" and "idiopathic" in alternate entries.

Signs and symptoms
Symptoms of JIA are often non-specific initially, and include lethargy, reduced physical activity, and poor appetite. The first manifestation, particularly in young children, may be limping. Children may also become quite ill, presenting with flu-like symptoms that persist. The cardinal clinical feature is persistent swelling of the affected joint(s), which commonly include the knee, ankle, wrist and small joints of the hands and feet. Swelling may be difficult to detect clinically, especially for joints such as those of the spine, sacroiliac joints, shoulder, hip and jaw, where imaging techniques such as ultrasound or MRI are very useful.

Pain is an important symptom. Morning stiffness that improves later in the day is a common feature. Late effects of arthritis include joint contracture (stiff, bent joint) and joint damage. Children with JIA vary in the degree to which they are affected by particular symptoms.Children may also have swollen joints.

Extra-articular
Eye disease: JIA is associated with inflammation in the front of the eye (specifically iridocyclitis, a form of chronic anterior uveitis), which affects about one child in five who has JIA, most commonly girls. This complication may not have any symptoms and can be detected by an experienced optometrist or ophthalmologist using a slit lamp. Most children with JIA are enrolled in a regular slit lamp screening program, as poorly controlled chronic anterior uveitis may result in permanent eye damage, including blindness.

Growth disturbance: Children with JIA may have reduced overall rate of growth, especially if the disease involves many joints or other body systems. Paradoxically, individually affected large joints (such as the knee) may grow faster, due to inflammation - induced, increased blood supply to the bone growth plates situated near the joints

Complications
JIA is a chronic disorder which if neglected can lead to serious complications. Proper follow up with health professionals can significantly reduce the chance of developing complications.

A form of eye inflammation called uveitis is common with some types of JIA. The inflamed eyes, if left untreated, can result in glaucoma, scars, cataracts and even blindness. Often the eye inflammation occurs without symptoms, or while the JIA is otherwise in remission, and thus it is important for all children to get regular eye checkups from an eye physician.

Growth retardation is common in children with JIA. Moreover, the medications (corticosteroids) used to treat JIA have potent side effects that can limit growth. Other muskuloskeletal issues may include joint contractures, muscle weakness or muscle loss, and osteoporosis.

Children who delay treatment or do not participate in physical therapy can often develop joint deformities of the hand and fingers. Over time hand function is lost and almost impossible to recover.

Causes
So far the actual cause of JIA remains a mystery. However, the disorder is autoimmune - meaning that the body's own immune system starts to attack and destroy cells and tissues (particularly in the joints) for no apparent reason. It is believed that the immune system gets provoked by changes in the environment or perhaps there is an error in the gene. Experimental studies have shown that certain viruses that have mutated may be able to trigger JIA. JIA appears to be more common in young girls and the disease is most common in Caucasians. Associated factors that may worsen or have been linked to rheumatoid arthritis include the following:


 * genetic predisposition; it appears that when one family member has been diagnosed with rheumatoid arthritis, the chances are higher that other family members or siblings may also develop arthritis


 * females are more likely to develop rheumatoid arthritis than males at all ages


 * there is a strong belief that psychological stress may worsen the symptoms of rheumatoid arthritis. However, when the emotional stress is under control the arthritis symptoms do not always disappear suggesting that the association is not straightforward


 * even though no distinct immune factor has been isolated as a cause of arthritis, there are some experts who believe that the triggering factor may be something like a virus which then disappears from the body after permanent damage is done


 * because rheumatoid arthritis is more common in women, there is a belief that perhaps sex hormones may be playing a role in causing or modulating arthritis. Unfortunately, neither sex hormone deficiency nor replacement has been shown to improve or worsen arthritis.

The cause of JIA, as the word idiopathic suggests, is unknown and currently an area of active research. Current understanding of JIA suggests that it arises in a genetically susceptible individual due to environmental factors.

Classification
The 3 major types of JIA are oligoarticular JIA, polyarticular JIA and systemic JIA.

Oligoarticular
Oligoarticular (or pauciarticular) JIA affects 4 or fewer joints in the first 6 months of illness. Oligo means few.

Oligoarticular is used with JIA terminology, and pauciarticular is used with JRA terminology.

Patients with oligoarticular JIA are more often ANA positive, when compared to other types of JIA.

Accounts for about 50% of JIA cases. Usually involves the large joints such as the knees, ankles, and elbows but smaller joints (such as the fingers and toes) may also be affected. The hip is not affected unlike polyarticular JIA. It is usually not symmetrical, meaning the affected joints are on one side of the body rather than on both sides simultaneously. Length discrepancy & muscles atrophy often happens which leads to asymmetric growth and risk of flexion contracture. Early childhood onset are at risk for developing a chronic iridocyclitis or an anterior uveitis, which is inflammation of the eye. This condition often goes unnoticed; therefore these children should be closely monitored by an optometrist. If ANA+, patient need routine eye exam every 3 months. If ANA- and older than 7 years old, can have eye exam every 6 months. Children with late childhood onset are at risk for sacroilitis and spondyloarthropathy.

Polyarticular
Polyarticular JIA affects 5 or more joints in the first 6 months of disease. This subtype can include the neck and jaw as well as the small joints usually affected. This type of JIA is more common in girls than in boys. Usually the smaller joints are affected in polyarticular JIA, such as the fingers and hands, although weight-bearing joints such as the knees, hips, and ankles may also be affected. The joints affected are usually symmetrical, meaning that it affects both joints on both sides of the body (such as both wrists.) Children with polyarticular JIA are also at risk for developing chronic iridocyclitis or uveitis (inflammation of the eye) and should also be monitored by an ophthalmologist. Rheumatoid factor may be positive i.e. seropositive in children with polyarticular JIA occurring between 9-16 years of age and is associated with HLA DR4 and HLA DW4. This group has poorer prognosis with about 50% progressing to severe disabiling arthritis, persisting into adulthood. It is generally seronegative in JIA occurring below 10 years of age with a milder disease process and responds better to treatment. Seropositivity is rare in children with systemic JIA. Due to the greater number of joints affected by polyarticular JIA as well as the tendency to worsen over time, polyarticular JIA needs to be treated aggressively.

Systemic
Systemic JIA is characterized by arthritis, fever, which typically is higher than the low-grade fever associated with polyarticular and a salmon pink rash. It accounts for 10-20% of JIA and affects males and females equally, unlike the other two subtypes of JIA, and affects adolescents. It generally involves both large & small joints. Systemic JIA can be challenging to diagnose because the fever and rash come and go. Fever can occur at the same time every day or twice a day (often in late afternoon or evening) with a spontaneous rapid return to baseline (vs. Septic Arthritis of continuous fever). The rash often occurs with fever. It is a discrete, salmon-pink macules of different sizes. It migrates to different locations on skin, rarely persisting in one location more than one hour. The rash is commonly seen on trunk and proximal extremities or over pressure areas.

Systemic JIA may have internal organ involvement: Hepatosplenomegaly, Lymphadenopathy, Serositis, Hepatitis, Tenosynovitis, etc.

It is also known as "systemic onset juvenile rheumatoid arthritis".

A polymorphism in macrophage migration inhibitory factor has been associated with this condition.

It is sometimes called "adolescent-onset Still's disease", to distinguish it from adult-onset Still's disease. However, there is some evidence that the two conditions are closely related.

Rheumatoid factor and ANA are generally negative in systemic JIA.

Other types
Some doctors include two other, less common forms: enthesitis-related arthritis and psoriatic JIA. Enthesitis is an inflammation of the insertion points of the tendons. This form occurs most often in boys older than 8, characteristically causes back pain, and is linked to ankylosing spondylitis and inflammatory bowel disease. Psoriatic JIA occurs most often in girls, in conjunction with psoriasis, although joint problems may precede the skin manifestations by several years. drop injection

Diagnosis
Diagnosis of JIA is difficult because joint pain in children can be from many other causes. There is no single test that can confirm the diagnosis and most physicians use a combination of blood tests, x rays and the clinical presentation to make an initial diagnosis of JIA. The blood tests measure antibodies and the rheumatoid factor. Unfortunately, the rheumatoid factor is not present in all children with JIA. Moreover in some cases the blood work is somewhat normal. X rays are obtained to ensure that the joint pain is not from a fracture, cancer, infection or a congenital abnormality.

In most cases, fluid from the joint is aspirated and analyzed. This test often helps in making a diagnosis of JIA by ruling out other causes of joint pain.

Differential Diagnosis
One possible differential diagnosis for JIA is Farber disease. Farber disease is a rare, fatal, genetic lysosomal disorder caused by a deficiency of the enzyme acid ceramidase. It has symptoms similar to JIA including swelling, stiffness and pain at the joints. These joint abnormalities are progressive and will develop during early infancy in a patient with Farber disease. Patients with Farber disease typically have subcutaneous nodules and a hoarse or weak voice due to growth of nodules on the larynx. A Farber disease diagnosis can be confirmed via gene sequencing.

Treatment
JIA is best treated by a multidisciplinary team. The major emphasis of treatment for JIA is to help the child regain normal level of physical and social activities. This is accomplished with the use of physical therapy, pain management strategies and social support. Another emphasis of treatment is to control inflammation as well as extra-articular symptoms quickly. Doing so should help to reduce joint damage, and other symptoms, which will, help reduce levels of permanent damage leading to disability

There have been very beneficial advances in drug treatment over the last 20 years. Most children are treated with non-steroidal anti-inflammatory drugs and intra-articular corticosteroid injections. Methotrexate, a disease modifying anti-rheumatic drug (DMARD) is a powerful drug which helps suppress joint inflammation in the majority of JIA patients with polyarthritis  (though less useful in systemic arthritis). Newer drugs have been developed recently, such as TNF alpha blockers, such as etanercept. There is no controlled evidence to support the use of alternative remedies such as specific dietary exclusions, homeopathic treatment or acupuncture. However, an increased consumption of omega-3 fatty acids proved to be beneficial in two small studies.

Celecoxib has been found effective in one study.

Other aspects of managing JIA include physical and occupational therapy. Therapists can recommend the best exercise and also make protective equipment. Moreover, the child may require the use of special supports, ambulatory devices or splints to help them ambulate and function normally.

Surgery is only used to treat the most severe cases of JIA. In all cases, surgery is used to remove scars and improve joint function.

Home remedies that may help JIA includes getting regular exercises to increase muscle strength and joint flexibility. Swimming is perhaps the best activity for all children with JIA. Stiffness and swelling can also be reduced with application of cold packs but a warm bath or shower can also improve joint mobility.

Occupational therapy
The best approach to treating a child with JIA involves a team of medical professionals including a rheumatologist, occupational therapist (OT), physical therapist, nurse and social worker.

The role of the OT is to help children participate as fully and independently as possible in their daily activities or "occupations", by preventing psychological and physical dependency. The aim is to maximize quality of life, and minimize disruption to the child’s and family’s life. OTs work with children, their families and schools, to come up with an individualized plan which is based on the child’s condition, limitations, strengths and goals. This is accomplished by ongoing assessments of a child’s abilities and social functioning. The plan may include the use of a variety of assistive devices, such as splints, that help a person perform tasks. The plan may also involve changes to the home, encouraging use of uninvolved joints, as well as providing the child and their family with support and education about the disease and strategies for managing it. OT interventions will be changed depending on the progression and remission of JIA, in order to promote age-appropriate self-sufficiency. Early OT involvement is essential. Interventions taught by an OT can help a child adapt and adjust to the challenges of JIA throughout the rest of their life.

Self-care
OTs can provide many strategies to assist children in their dressing routine. Clothes with easy openings and Velcro, as well as devices, such as buttonhooks and zipper pulls can be used. For children who have difficulty bending, a long handled reacher and sock aid is recommended. OTs may also show children how to sit during dressing so less strain is put on their joints.

OTs can help children maintain cleanliness through recommending assistive devices. For children who have trouble reaching all areas of their body, a long handled sponge with a soft grip can be provided. If children find it difficult to sit in a bath or stand in a shower, an OT can prescribe a bath bench or bath seat to be installed to help the child remain in a pain free position. If tooth brushing is challenging, a toothbrush with a larger, soft grip or an electric toothbrush may be recommended. For flossing, a flosser with an adapted handle may be provided. Long handled hairbrushes may be used by children who have difficulty reaching the back of their head. Razors handles can be adapted for easier grip, or an electric razor may be used for shaving. The OT can also show girls wishing to use make-up, ways of increasing the sizes of the handles of make-up application tools for easier grip.

For children with pain in their hands and wrists, utensils and devices that are lightweight with large handles as well as other devices (such as angled knives, strap-on utensils, jar and bottle openers, turning handles, door knob extensions, etc.) can be provided to make the task easier, less painful and more enjoyable. Tilted glasses can be used for children who have neck stiffness. Education can be provided about good eating habits that help control bone loss caused by inactivity and drug side effects. Occupational therapists provide a myriad of strategies to assist children with JIA in performing self-care tasks.

Leisure
One of the best ways OTs can help children with JIA participate in activities with their friends is by helping them make their home exercise programs into play. Exercises are prescribed by both physiotherapists and OTs to increase the amount a child can move a joint and strengthen the joint to decrease pain and stiffness and prevent further limitations in their joint movements. OTs can provide children with age appropriate games and activities to allow the children to practice their exercises while playing and socializing with friends. Examples are crafts, swimming and non-competitive sports.

OTs will often prescribe custom made orthotics which are devices that support and correct body position and function. Orthotics help keep the child’s body in good alignment. Orthotics reduce discomfort in the legs and back when the child participates in physical activities such as sports. Splints can be used to support the joints during activity, to reduce the child’s pain and increase participation in their preferred leisure activities. Resting splints may be prescribed for children to wear during the night to reduce swelling and stiffness in joints, allowing children to have less pain and stiffness while participating in play activities. Furthermore, working splints are used to support the joint and relieve pain while working the with hands such as during crafts. A series of casts might be used to gradually extend shortened muscles allowing for increased participation in leisure activities.

OTs can help a child learn how to interact with their classmates and friends by collaboratively brainstorming strategies, role playing and modeling. OTs also help children see what activities they are good at and which ones give them difficulty. Furthermore, OTs can help children learn to communicate their pain to others. Benefits of OT treatment include: improved social interaction, improved self-confidence and a positive self-image. OTs can help children build friendships with other children suffering from similar diseases to help them feel less alone or less different from others. Many OTs run summer camps for children with similar diseases so children can get to know others with their disease. Education sessions on JIA and leisure, and activities such as swimming, canoeing and nature trails are common.

For children who find that cool or damp weather make it hard to play with friends outside, OTs can give ideas for clothing that will keep the child warm and dry without limiting movement. An example of this is biking gloves which allow children to move their fingers while still keeping their hands warm, as opposed to large winter gloves which limit hand function. Warm pajamas and electric blankets can reduce pain and improve sleep.

Productivity
Children with JIA often require school activity modifications due to disease symptoms. OTs can work with families and schools to improve attendance at school. Therapists help children to succeed by providing ways for full participation at school by working with staff, taking part in activity planning and assessing the need for accommodations and adaptations.

OTs work with children, families and schools to develop strategies for helping children manage pain, stiffness and tiredness, which may sometimes limit their ability to participate in school related activities. A balanced plan will allow children to get enough activity that they do not stiffen up, but also enough rest that they do not tire. For example, a plan might be worked out with a teacher so a child will be allowed to stand and stretch during prolonged sitting, perform modified gym activities or take rest breaks during gym classes. Other common management strategies taught by OTs include waking up early before school and taking a hot bath and then doing exercises to reduce stiffness and pain throughout the day. Using proper body movements when performing activities helps reduce strain on joints and thereby decrease pain and stiffness. OTs can also teach children how to relax their muscles.

OTs may prescribe special equipment for children at school to make them more comfortable. Desks and chairs of a proper height for children are very important. The desk may have the ability to tilt into a comfortable position for writing. Pencils and pens with larger, softer grips can be used to make writing easier and less painful. Special keyboards may be prescribed to keep a child’s arms in a position that will reduce strain on joints when using a computer. OTs can work with teachers to educate them about a child’s condition, limitations and ways they can help make school a positive experience for the child. Recommendations might include two sets of textbooks, one for home one for school, to prevent carrying a heavy load of books. Additional recommendations may involve a reduced amount of writing and typing, sitting on a chair instead of the floor, extra time to move between classes, an elevator key for schools that have elevators but restrict them to students with health problems, providing a student note-taker, and extra time to complete assignments.

As teenagers become adults, OTs can start working with them regarding their future education and employment plans. OTs can assist teenagers in finding ways to tell their employers about their disease in a positive way. OTs can also help teenagers understand their rights as an employee with a disability. Assistance with obtaining funding for post-secondary education might be provided. OTs may help teenagers set up volunteering in the community, to gain experience and self-confidence in their abilities. It is important that teenagers with JIA understand how to take care of themselves and manage their disease when working full-time or attending university. OTs can help teenagers develop strategies that will allow them to function at their greatest ability by taking care of their health.

Prognosis
With proper therapy, some children do improve with time and lead normal lives. However, severe cases of JIA which are not treated promptly can lead to poor growth and worsening of joint function. In the last two decades, significant improvements have been made in treatment of JIA and most children can lead a decent quality of life. The prognosis of JIA depends on prompt recognition and treatment. Many children with JIA have gone on to play professional sports and have a variety of successful careers.

Onset
JIA occurs in both sexes, but, like other rheumatological diseases, is more common in females. Symptoms onset is frequently dependent on the subtype of JIA (see Types of JIA) and is from the pre-school years to the early teenage years.

Prevalence
Juvenile idiopathic arthritis affects somewhere between 8 and 150 of every 100,000 children, depending on the analysis. Of these children, 50 percent have pauciarticular JIA, 40 percent have polyarticular JIA and 10 percent have systemic JIA. It has been shown, that in a preselected group (children under 16 years with orthodontic treatment need) prevalence rises to 1 out of 100 (0.88% out of 1024 children).

Famous patients
Rosemary Sutcliff, author.