Juvenile Arthritis

Definition

Juvenile arthritis (JA), also called juvenile rheumatoid arthritis (JRA), refers to a number of different conditions, all of which strike children, and all of which have immune-mediated joint inflammation as their major manifestation. JRA is also known as juvenile idiopathic arthritis or JIA. The European League Against Rheumatism, or EULAR, refers to the disorder as juvenile chronic arthritis, or JCA.

Description

The skeletal system of the body is made up of different types of the strong, fibrous tissue known as connective tissue. Bone, cartilage, ligaments, and tendons are all forms of connective tissue which have different compositions, and thus different characteristics.

The joints are structures which hold two or more bones together. Some joints (synovial joints) allow for movement between the bones being joined (called articulating bones). The simplest model of a synovial joint involves two bones, separated by a slight gap called the joint cavity. The ends of each articular bone are covered by a layer of cartilage. Both articular bones and the joint cavity are surrounded by a tough tissue called the articular capsule. The articular capsule has two components: the fibrous membrane on the outside, and the synovial membrane (or synovium) on the inside. The fibrous membrane may include tough bands of fibrous tissue called ligaments, which are responsible for providing support to the joints. The synovial membrane has special cells and many capillaries (tiny blood vessels). This membrane produces a supply of synovial fluid which fills the joint cavity, lubricates it, and helps the articular bones move smoothly about the joint.

In JA, the synovial membrane becomes intensely inflamed. Usually thin and delicate, the synovium becomes thick and stiff, with numerous infoldings on its surface. The membrane becomes invaded by white blood cells, which produce a variety of destructive chemicals. The cartilage along the articular surfaces of the bones may be attacked and destroyed, and the bone, articular capsule, and ligaments may begin to be worn away (eroded). These processes severely interfere with movement in the joint.

JA specifically refers to chronic arthritic conditions which affect a child under the age of 16 years, and which last for a minimum of three to six months. JA is often characterized by a waxing and waning course, with flares separated by periods of time during which no symptoms are noted (remission). Some literature refers to JA as juvenile rheumatoid arthritis, although most types of JA differ significantly from the adult disease called rheumatoid arthritis, in terms of symptoms, progression, and prognosis.

Causes and symptoms

A number of different causes have been sought to explain the onset of JA. There seems to be some genetic link, based on the fact that the tendency to develop JA sometimes runs in a particular family, and based on the fact that certain genetic markers are more frequently found in patients with JA and other related diseases. Many researchers have looked for some infectious cause for JA, but no clear connection to a particular organism has ever been made. JA is considered by some to be an autoimmune disorder. Autoimmune disorders occur when the body's immune system mistakenly identifies the body's own tissue as foreign, and goes about attacking those tissues, as if trying to rid the body of an invader (such as a bacteria, virus, or fungi). While an autoimmune mechanism is strongly suspected, certain markers of such a mechanism (such as rheumatoid factor, often present in adults with such disorders) are rarely present in children with JA.

Joint symptoms of arthritis may include stiffness, pain, redness and warmth of the joint, and swelling. Bone in the area of an affected joint may grow too quickly, or too slowly, resulting in limbs which are of different lengths. When the child tries to avoid moving a painful joint, the muscle may begin to shorten from disuse. This is called a contracture.

Symptoms of JA depend on the particular subtype. According to criteria published by the American College of Rheumatology (ACR) in 1973 and modified in 1977, JRA is classified by the symptoms that appear within the first six months of the disorder:

• Pauciarticular JA: This is the most common and the least severe type of JA, affecting about 40-60% of all JA patients. This type of JA affects fewer than four joints, usually the knee, ankle, wrist, and/or elbow. Other more general (systemic) symptoms are usually absent, and the child's growth usually remains normal. Very few children (less than 15%) with pauciarticular JA end up with deformed joints. Some children with this form of JA experience painless swelling of the joint. Some children with JA have a serious inflammation of structures within the eye, which if left undiagnosed and untreated could even lead to blindness. This condition is known as uveitis, and affects about 20% of children diagnosed with JRA. While many children have cycles of flares and remissions, in some children the disease completely and permanently resolves within a few years of diagnosis.
• Polyarticular JA: About 40% of all cases of JA are of this type. More girls than boys are diagnosed with this form of JA. This type of JA is most common in children up to age three, or after the age of 10. Polyarticular JA affects five or more joints simultaneously. This type of JA usually affects the small joints of both hands and both feet, although other large joints may be affected as well. Some patients with arthritis in their knees will experience a different rate of growth in each leg. Ultimately, one leg will grow longer than the other. About half of all patients with polyarticular JA have arthritis of the spine and/or hip. Some patients with polyarticular JA will have other symptoms of a systemic illness, including anemia (low red blood cell count), decreased growth rate, low appetite, low-grade fever, and a slight rash. The disease is most severe in those children who are diagnosed in early adolescence. Some of these children will test positive for a marker present in other autoimmune disorders, called rheumatoid factor (RF). RF is found in adults who have rheumatoid arthritis. Children who are positive for RF tend to have a more severe course, with a disabling form of arthritis which destroys and deforms the joints. This type of arthritis is thought to be the adult form of rheumatoid arthritis occurring at a very early age.
• Systemic onset JA: Sometimes called Still disease (after a physician who originally described it), this type of JA occurs in about 10-20% of all patients with JA. Boys and girls are equally affected, and diagnosis is usually made between the ages of 5-10 years. The initial symptoms are not usually related to the joints. Instead, these children have high fevers; a rash; decreased appetite and weight loss; severe joint and muscle pain; swollen lymph nodes, spleen, and liver; and serious anemia. Some children experience other complications, including inflammation of the sac containing the heart (pericarditis ); inflammation of the tissue lining the chest cavity and lungs (pleuritis); and inflammation of the heart muscle (myocarditis ). The eye inflammation often seen in pauciarticular JA is uncommon in systemic onset JA. Symptoms of actual arthritis begin later in the course of systemic onset JA, and they often involve the wrists and ankles. Many of these children continue to have periodic flares of fever and systemic symptoms throughout childhood. Some children will go on to develop a polyarticular type of JA.
• Spondyloarthropathy: This type of JA most commonly affects boys older than eight years of age. The arthritis occurs in the knees and ankles, moving over time to include the hips and lower spine. Inflammation of the eye may occur occasionally, but usually resolves without permanent damage.
• Psoriatic JA: This type of arthritis usually shows up in fewer than four joints, but goes on to include multiple joints (appearing similar to polyarticular JA). Hips, back, fingers, and toes are frequently affected. A skin condition called psoriasis accompanies this type of arthritis. Children with this type of JA often have pits or ridges in their fingernails. The arthritis usually progresses to become a serious, disabling problem.

As of 2003, there is some disagreement among specialists about the classification of JRA. Some prefer the EULAR classification, also introduced in 1977, to the ACR system. In 1997, the World Health Organization (WHO) met in Durban and issued a new classification system for JRA known as the Durban criteria, in an attempt to standardize definitions of the various subtypes of JRA. None of the various classification systems, however, are considered fully satisfactory as of early 2004.

Diagnosis

Diagnosis of JA is often made on the basis of the child's collection of symptoms. Laboratory tests often show normal results. Some nonspecific indicators of inflammation may be elevated, including white blood cell count, erythrocyte sedimentation rate, and a marker called C-reactive protein. As with any chronic disease, anemia may be noted. Children with an extraordinarily early onset of the adult type of rheumatoid arthritis will have a positive test for rheumatoid factor.

Treatment

Treating JA involves efforts to decrease the amount of inflammation, in order to preserve movement. Medications which can be used for this include nonsteroidal anti-inflammatory agents (such as ibuprofen and naproxen). Oral (by mouth) steroid medications are effective, but have many serious side effects with long-term use. Injections of steroids into an affected joint can be helpful. Steroid eye drops are used to treat eye inflammation. Other drugs which have been used to treat JA include methotrexate, sulfasalazine, penicillamine, and hydroxychloroquine. Physical therapy and exercises are often recommended in order to improve joint mobility and to strengthen supporting muscles. Occasionally, splints are used to rest painful joints and to try to prevent or improve deformities.

The Food and Drug Administration (FDA) approved a new drug, etanercept, marketed under the brand name Enbrel, in 1999. It is the most dramatic advancement in treating JRA in recent years. A study by Children's Hospital Medical Center in Cincinnati, Ohio, released in 1999, showed the drug was effective in 75% of children with severe JRA. The drug eases joint pain, reduces swelling, and improves mobility.

In 2003, a group of Japanese researchers noted that the blood serum of patients with JRA contains elevated levels of interleukin-6, a cytokine (nonantibody protein) that is critical to regulation of the immune system and blood cell formation. Because interleukin-6 is also associated with inflammation, the researchers think that compounds inhibiting the formation of interleukin-6 might provide new treatment options for JRA.

Alternative treatment

Alternative treatments that have been suggested for arthritis include juice therapy, which can work to detoxify the body, helping to reduce JA symptoms. Some recommended fruits and vegetables to include in the juice are carrots, celery, cabbage, potatoes, cherries, lemons, beets, cucumbers, radishes, and garlic. Tomatoes and other vegetables in the nightshade (potatoes, eggplant, red and green peppers) are discouraged. As an adjunct therapy, aromatherapy preparations utilize cypress, fennel, and lemon. Massage oils include rosemary, benzoin, chamomile, camphor, juniper, and lavender. Other types of therapy which have been used include acupuncture, acupressure, and body work. Nutritional supplements that may be beneficial include large amounts of antioxidants (vitamins C, A, E, zinc, selenium, and flavenoids), as well as B vitamins and a full complement of minerals (including boron, copper, manganese). Other nutrients that assist in detoxifying the body, including methionine, cysteine, and other amino acids, may also be helpful. A number of autoimmune disorders, including JA, seem to have a relationship to food allergies. Identification and elimination of reactive foods may result in a decrease in JA symptoms. Constitutional homeopathy can also work to quiet the symptoms of JA and bring about balance to the whole person.

Prognosis

The prognosis for pauciarticular JA is quite good, as is the prognosis for spondyloarthropathy. Polyarticular JA carries a slightly worse prognosis. RF-positive polyarticular JA carries a difficult prognosis, often with progressive, destructive arthritis and joint deformities. Systemic onset JA has a variable prognosis, depending on the organ systems affected, and the progression to polyarticular JA. About 1-5% of all JA patients die of such complications as infection, inflammation of the heart, or kidney disease.

KEY TERMS

Articular bones— Two or more bones which are connected with each other via a joint.

Cytokine— A general term for nonantibody proteins released by a specific type of cell as part of the body's immune response.

Idiopathic— Of unknown cause or spontaneous origin. JRA is sometimes called juvenile idiopathic arthritis or JIA because its causes are still not fully known.

Joint— A structure that holds two or more bones together.

Rheumatology— The branch of medicine that specializes in the diagnosis and treatment of disorders affecting the muscles and joints.

Synovial joint— A particular type of joint that allows for movement in the articular bones.

Synovial membrane— The membrane that lines the inside of the articular capsule of a joint and produces a lubricating fluid called synovial fluid.

Uveitis— Inflammation of the pigmented vascular covering of the eye, which includes the choroid, iris, and ciliary body. Uveitis is a common complication of JRA.

Prevention

Because so little is known about what causes JA, there are no recommendations available for how to avoid developing it.

Resources

BOOKS

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Juvenile Rheumatoid Arthritis." Section 19, Chapter 270 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2002.

Behrman, Richard, et al., editors. Nelson Textbook of Pediatrics. 16th ed. Philadelphia: W. B. Saunders Co., 2000.

Kredich, Deborah Welt. "Juvenile Rheumatoid Arthritis." In Rudolph's Pediatrics, edited by Abraham M. Rudolph. Stamford:McGraw-Hill, 2002.

Peacock, Judith. Juvenile Arthritis. Mankato, MN: LifeMatters Books, 2000.

PERIODICALS

de Boer, J., N. Wulffraat, and A. Rothova. "Visual Loss in Uveitis of Childhood." British Journal of Ophthalmology 87 (July 2003): 879-884.

Henderson, Charles W. "Etancercept a Dramatic Advancement in Treatment, Say Researchers." Immunotherapy Weekly April 2, 2000.

Kotaniemi, K., A. Savolainen, A. Karma, and K. Aho. "Recent Advances in Uveitis of Juvenile Idiopathic Arthritis." Survey of Ophthalmology 48 (September-October 2003): 489-502.

Larkin, Marilynn. "Juvenile Arthritis Helped by Resistance Exercise." Lancet November 20, 1999: 1797.

Manners, P., J. Lesslie, D. Speldewinde, and D. Tunbridge. "Classification of Juvenile Idiopathic Arthritis: Should Family History Be Included in the Criteria?" Journal of Rheumatology 30 (August 2003): 1857-1863.

Moran, M. "Autoimmune Diseases Could Share Common Genetic Etiology." American Medical News 44, no. 38 (October 8, 2001): 38.

Yokota, S. "Interleukin 6 as a Therapeutic Target in Systemic-Onset Juvenile Idiopathic Arthritis." Current Opinion in Rheumatology 15 (September 2003): 581-586.

ORGANIZATIONS

American College of Rheumatology. 1800 Century Place, Suite 250, Atlanta, GA 30345. (404) 633-3777. 〈http://www.rheumatology.org〉.

Arthritis Foundation. 1330 West Peachtree St., Atlanta, GA 30309. (404) 872-7100. 〈http://www.arthritis.org〉.

National Arthritis and Musculoskeletal and Skin Diseases Information Clearinghouse. National Institutes of Health, 1 AMS Circle, Bethesda, MD 20892. (301) 495-4484. 〈http://www.nih.gov/niams〉.

OTHER

National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Questions and Answers About Juvenile Rheumatoid Arthritis. NIH Publication No. 01-4942. Bethesda, MD: NIAMS, 2001. 〈http://www.niams.nih.gov/hi/topics/juvenile_arthritis/juvarthr.htm〉.

Juvenile arthritis

Definition

Juvenile arthritis (JA) refers to a number of different conditions, all of which strike children and all of which have joint inflammation as their major manifestation. The condition is also referred to as juvenile rheumatoid arthritis.

Description

The skeletal system of the body is made up of different types of the strong, fibrous tissue known as connective tissue. Bone, cartilage, ligaments, and tendons are all forms of connective tissue which have different compositions and different characteristics.

The joints are structures that hold two or more bones together. Some joints (synovial joints) allow for movement between the bones being joined (called articulating bones). The simplest model of a synovial joint involves two bones, separated by a slight gap called the joint cavity. The ends of each articular bone are covered by a layer of cartilage. Both articular bones and the joint cavity are surrounded by a tough tissue called the articular capsule. The articular capsule has two components: the fibrous membrane on the outside and the synovial membrane (or synovium) on the inside. The fibrous membrane may include tough bands of fibrous tissue called ligaments, which are responsible for providing support to the joints. The synovial membrane has special cells and many capillaries (tiny blood vessels). This membrane produces a supply of synovial fluid which fills the joint cavity, lubricates it, and helps the articular bones move smoothly about the joint.

In JA, the synovial membrane becomes intensely inflamed. Usually thin and delicate, the synovium becomes thick and stiff, with numerous infoldings on its surface. The membrane becomes invaded by white blood cells, which produce a variety of destructive chemicals. The cartilage along the articular surfaces of the bones may be attacked and destroyed, and the bone, articular capsule, and ligaments may begin to be worn away (eroded). These processes severely interfere with movement in the joint.

JA specifically refers to chronic arthritic conditions which affect a child under the age of 16 years and which last for a minimum of three to six months. JA is often characterized by a waxing and waning course, with flares separated by periods during which no symptoms are noted (remission). Some literature refers to JA as juvenile rheumatoid arthritis, although most types of JA differ significantly from the adult disease called rheumatoid arthritis, in terms of symptoms, progression, and prognosis.

Demographics

Between five and 18 of every 100,000 children develop juvenile rheumatoid arthritis each year; the overall prevalence is approximately 30–150 per 100,000. More than 65,000 young people in the United States develop it each year. It can affect children as young as two years of age.

Causes and symptoms

A number of different causes have been sought to explain the onset of JA. There seems to be some genetic link, based on the fact that the tendency to develop JA sometimes runs in a particular family and based on the fact that certain genetic markers are more frequently found in patients with JA and other related diseases. Many researchers have looked for some infectious cause for JA, but no clear connection to a particular organism had been made as of 2004. JA is considered by some to be an autoimmune disorder. Autoimmune disorders occur when the body's immune system mistakenly identifies the body's own tissue as foreign and goes about attacking those tissues, as if trying to rid the body of an invader (such as a bacteria, virus, or fungi). While an autoimmune mechanism is strongly suspected, certain markers of such a mechanism (such as rheumatoid factor, often present in adults with such disorders) are rarely present in children with JA.

Joint symptoms of arthritis may include stiffness, pain , redness and warmth of the joint, and swelling. Bone in the area of an affected joint may grow too quickly or too slowly resulting in limbs which are of different lengths. When the child tries to avoid moving a painful joint, the muscle may begin to shorten from disuse. This condition is called a contracture.

Symptoms of JA depend on the particular subtype. JA is classified by the symptoms which appear within the first six months of the disorder:

• Pauciarticular JA: The most common and the least severe type of JA affects about 40–60 percent of all JA patients. This type of JA affects fewer than four joints, usually the knee, ankle, wrist, and/or elbow. Other more general (systemic) symptoms are usually absent, and the child's growth usually remains normal. Very few children (fewer than 15 percent) with pauciarticular JA end up with deformed joints. Some children with this form of JA experience painless swelling of the joint. Some children with JA have a serious inflammation of structures within the eye, which if left undiagnosed and untreated could even lead to blindness. While many children have cycles of flares and remissions, in some children the disease completely and permanently resolves within a few years of diagnosis.
• Polyarticular JA: About 40 percent of all cases of JA are of this type. More girls than boys are diagnosed with this form of JA, and it is most common in children up to age three or after the age of ten. Polyarticular JA affects five or more joints simultaneously. This type of JA usually affects the small joints of both hands and both feet, although other large joints may be affected as well. Some patients with arthritis in their knees will experience a different rate of growth in each leg. Ultimately, one leg will grow longer than the other. About half of all patients with polyarticular JA have arthritis of the spine and/or hip. Some patients with polyarticular JA will have other symptoms of a systemic illness, including anemia (low red blood cell count), decreased growth rate, low appetite, low-grade fever , and a slight rash. The disease is most severe in those children who are diagnosed in early adolescence . Some of these children test positive for a marker present in other autoimmune disorders, called rheumatoid factor (RF), which is found in adults who have rheumatoid arthritis. Children who are positive for RF tend to have a more severe course, with a disabling form of arthritis that destroys and deforms the joints. This type of arthritis is thought to be the adult form of rheumatoid arthritis occurring at a very early age.
• Systemic onset JA: Sometimes called Still disease (after a physician who originally described it), this type of JA occurs in about 10–20 percent off all patients with JA. Boys and girls are equally affected, and diagnosis is usually made between the ages of five and 10 years. The initial symptoms are not usually related to the joints. Instead, these children have high fevers; a rash; decreased appetite and weight loss; severe joint and muscle pain; swollen lymph nodes, spleen, and liver; and serious anemia. Some children experience other complications, including inflammation of the sac containing the heart (pericarditis); inflammation of the tissue lining the chest cavity and lungs (pleuritis); and inflammation of the heart muscle (myocarditis). The eye inflammation often seen in pauciarticular JA is uncommon in systemic onset JA. Symptoms of actual arthritis begin later in the course of systemic onset JA, and they often involve the wrists and ankles. Many of these children continue to have periodic flares of fever and systemic symptoms throughout childhood. Some children go on to develop a polyarticular type of JA.
• Spondyloarthropathy: This type of JA most commonly affects boys older than eight years of age. The arthritis occurs in the knees and ankles, moving over time to include the hips and lower spine. Inflammation of the eye may occur occasionally but usually resolves without permanent damage.
• Psoriatic JA: This type of arthritis usually shows up in fewer than four joints but goes on to include multiple joints (appearing similar to polyarticular JA). Hips, back, fingers, and toes are frequently affected. A skin condition called psoriasis accompanies this type of arthritis. Children with this type of JA often have pits or ridges in their fingernails. The arthritis usually progresses to become a serious, disabling problem.

When to call the doctor

A pediatrician, family physician, or other primary care doctor frequently manages the treatment of a child with JA, often with the help of other doctors. Depending on the patient's and parents' wishes and the severity of the disease, the team of doctors may include pediatric rheumatologists (doctors specializing in childhood arthritis), ophthalmologists (eye doctors), orthopaedic surgeons (bone specialists), and physiatrists (rehabilitation specialists), as well as physical and occupational therapists. The main goals of treatment are to preserve a high level of physical and social functioning and maintain a good quality of life. To achieve these goals, doctors recommend treatments to reduce swelling; maintain full movement in the affected joints; relieve pain; and identify, treat, and prevent complications. Most children with JA need medication and physical therapy to reach these goals.

Diagnosis

Diagnosis of JA is often made on the basis of the child's collection of symptoms. Laboratory tests often show normal results. Some nonspecific indicators of inflammation may be elevated, including white blood cell count, erythrocyte sedimentation rate, and a marker called C-reactive protein. As with any chronic disease, anemia may be noted. Children with an extraordinarily early onset of the adult type of rheumatoid arthritis have a positive test for rheumatoid factor.

Treatment

Treating JA involves efforts to decrease the amount of inflammation in order to preserve movement. Medications which can be used for this include nonsteroidal anti-inflammatory agents (such as ibuprofen and naproxen). Oral (by mouth) steroid medications are effective but have many serious side effects with long-term use. Injections of steroids into an affected joint can be helpful. Steroid eye drops are used to treat eye inflammation. Other drugs that have been used to treat JA include methotrexate, sulfasalazine, penicillamine, and hydroxychloroquine. Physical therapy and exercises are often recommended in order to improve joint mobility and to strengthen supporting muscles. Occasionally, splints are used to rest painful joints and to try to prevent or reduce deformities.

Alternative treatment

Alternative treatments that have been suggested for arthritis include juice therapy, which can work to detoxify the body, helping to reduce JA symptoms. Some recommended fruits and vegetables to include in the juice are carrots, celery, cabbage, potatoes, cherries, lemons, beets, cucumbers, radishes, and garlic. However, for children with osteoarthritis, citrus fruits and vegetables from the nightshade family, including potatoes, tomatoes, peppers, and eggplant, should be avoided since they can promote swelling. As an adjunct therapy, aromatherapy preparations use cypress, fennel, and lemon. Massage oils include rosemary, benzoin, chamomile, camphor, juniper, and lavender. Other types of therapy that have been used for JA include acupuncture, acupressure, and bodywork. Nutritional supplements that may be beneficial include large amounts of antioxidants (vitamins C, A, E, zinc, selenium, and flavenoids), as well as B vitamins and a full complement of minerals (including boron, copper, and manganese). Other nutrients that assist in detoxifying the body, including methionine, cysteine, and other amino acids, may also be helpful. A number of autoimmune disorders, including JA, seem to have a relationship to food allergies . Identification and elimination of reactive foods may result in a decrease in JA symptoms. Constitutional homeopathy can also work to quiet the symptoms of JA and bring about balance to the whole person.

Nutritional concerns

When female patients were compared to agematched normals, greater than one serving per week of grilled (broiled) or baked fish (other than tuna) was associated with a decreased risk of disease. This inverse association was stronger than that for omega-3 fatty acid intake alone. In another study, patients with active disease randomly received treatment with or without a diet in which the energy consumption was adjusted to normal standards for body-weight, and the intake of fish and antioxidants was increased. After six months, those following the diet demonstrated significant improvement in the duration of morning stiffness, the number of swollen joints, and pain status.

Several studies, some of which were controlled, have found beneficial effects from a vegetarian or vegan diet. In one study, for example, patients randomly received either an uncooked vegan diet or a control diet for three months. Those on the vegan diet experienced subjective relief of rheumatic stiffness and joint swellings and an improvement in general wellbeing. After returning to the meat diet, these symptoms worsened. The degree of tender joints remained unchanged in controls, but in the diet group their number decreased significantly.

Prognosis

The prognosis for pauciarticular JA is quite good, as is the prognosis for spondyloarthropathy. Polyarticular JA carries a slightly worse prognosis. RF-positive polyarticular JA carries a difficult prognosis, often with progressive, destructive arthritis and joint deformities. Systemic onset JA has a variable prognosis, depending on the organ systems affected and the progression to polyarticular JA. About 1–5 percent of all JA patients die of such complications as infection, inflammation of the heart, or kidney disease.

Prevention

Because so little is known about what causes JA, there are no recommendations available for ways to avoid developing it.

Parental concerns

JA affects the entire family who must cope with the special challenges of this disease. JA can strain a child's participation in social and after-school activities and make schoolwork more difficult. There are several things that family members can do to help the child do well physically and emotionally. These include the following:

KEY TERMS

Articular bones —Two or more bones that are connected to each other via a joint.

Joint —The connection point where two bones meet.

Synovial joint —A fully moveable joint in which a synovial cavity is present between two articulating bones. Also called a diarthrosis.

Synovial membrane —The membrane that lines the inside of the articular capsule of a joint, and produces a lubricating fluid called synovial fluid.

• Ensure that the child receives appropriate medical care and follows the doctor's instructions. Many treatment options are available, and because JA is different in each child, what works for one may not work for another. If the medications that the doctor prescribes do not relieve symptoms or if they cause unpleasant side effects, patients and parents should discuss other choices with their doctor. A person with JA can be more active when symptoms are controlled.
• Encourage exercise and physical therapy for the child. For many young people, exercise and physical therapy play important roles in treating JA. Parents can arrange for children to participate in activities that the doctor recommends. During symptom-free periods, many doctors suggest playing team sports or doing other activities to help keep the joints strong and flexible and to provide play time with other children and encourage appropriate social development.
• Work closely with the school to develop a suitable lesson plan for the child and to educate the teacher and the child's classmates about JA. Some children with JA may be absent from school for prolonged periods and need to have the teacher send assignments home. Some minor changes such as an extra set of books or leaving class a few minutes early to get to the next class on time can be a great help. With proper attention, most children progress normally through school.
• Treat the child as normally as possible. Explain to the child that getting JA is nobody's fault. Some children believe that JA is a punishment for something they did. Consider joining a support group. The American Juvenile Arthritis Organization runs support groups for people with JA and their families. Support group meetings provide the chance to talk to other young people and parents of children with JA and may help a child and the family cope with the condition.

Resources

BOOKS

Gray, Susan H., and Serge Bloch. Living with Juvenile Rheumatoid Arthritis. Chanhassen, MN: Child's World, 2002.

The Official Patient's Sourcebook on Juvenile Rheumatoid Arthritis: A Revised and Updated Directory for the Internet Age. San Diego, CA: Icon Health Publications, 2002.

PERIODICALS

Boschert, Sherry. "Subtle Juvenile Rheumatoid Arthritis May Be More Common Than Thought." Pediatric News 37 (April 2003): 36.

Brunk, Doug. "When a Limp Signals Something More Serious: Make Sure to Examine the Hips." Family Practice News 34 (May 15, 2004): 50–51.

Labyak, Susan E., et al. "Sleep Quality in Children with Juvenile Rheumatoid Arthritis." Holistic Nursing Practice 17 (July-August 2003): 193–200.

ORGANIZATIONS

American Juvenile Arthritis Organization. 1330 West Peachtree St., Atlanta, GA 30309. Web site: <www.arthritis.org>.

National Institute of Arthritis and Musculoskeletal and Skin Diseases. 1 AMS Circle, Bethesda, MD 20892–3675. Web site: <www.niams.nih.gov/>.

WEB SITES

"Juvenile Rheumatoid Arthritis." KidsHealth, November 2001. Available online at <http://kidshealth.org/parent/medical/arthritis/jra.html> (accessed November 10, 2004).

"Types of Juvenile Arthritis." Arthritis Foundation, 2004. Available online at &lt;www.arthritis.org/conditions/DiseaseCenter/typesofJA.asp> (accessed November 10, 2004).

Rosalyn S. Carson-DeWitt Ken R. Wells

JUVENILE ARTHRITIS

DEFINITION

Juvenile arthritis (JA) refers to a number of different conditions with two characteristics in common. First, they all strike children. Second, they all involve inflammation of the joints.

DESCRIPTION

Humans can move their head, arms, legs, fingers, and toes because of joints. A joint is a structure where two or more bones come together. The elbow, for example, is a joint at which bones in the upper and lower arm come together.

Juvenile Arthritis: Words to Know

Articular capsule:

A tough tissue that surrounds a joint and the bones that come together at the joint.

Joint:

A structure that holds two or more bones together.

Synovial fluid:

A clear liquid that fills the spaces between bones in a joint cavitiy and helps the bones move across each other more easily.

Synovial membrane:

A membrane that covers the articular capsule in a joint and produces synovial fluid.

The space between the bones in a joint is occupied by a variety of other structures and fluids. These structures and fluids help the bones move more smoothly. One of the structures in a joint is the articular capsule. The articular capsule surrounds the bones that come together at a joint and the space between the joint. The articular capsule contains a thin covering called the synovial (pronounced si-NO-vee-uhl) membrane. The synovial membrane produces a clear liquid called synovial fluid that lubricates the space between the bones. The synovial fluid helps the bones slide across each other more easily.

In juvenile arthritis, the synovial membrane becomes very inflamed. Instead of being thin and flexible, it becomes thick and stiff. This change occurs when white blood cells invade the membrane. The white blood cells release chemicals that cause inflammation and attack other structures in the joint. The bones, ligaments, and other structures in the joint are worn away and the joint can no longer move smoothly and easily. Bending and turning movements cause pain and discomfort.

Juvenile arthritis is a joint inflammation that affects a child under the age of sixteen and that lasts for at least three to six months. The condition often goes through periods in which joints are very sore and painful and then return to normal. After a while the inflammation returns and joints are once again sore and painful.

CAUSES

A number of possible causes for JA have been suggested. Some researchers feel that the disorder may have a genetic basis. It seems to occur more often in some families than in others. Other researchers think the disorder may be caused by an infectious agent, such as a bacterium or a virus, but no such agent has ever been found.

Some evidence suggests that JA may be an autoimmune disorder (see autoimmune disorder entry). An autoimmune disorder is one in which the body's immune system becomes confused. It behaves as if some normal part of a person's body is actually a foreign substance. The immune system then sets out to attack and destroy that part of the body. According to this explanation, a person's immune system mistakenly attacks his or her joints, causing the symptoms of juvenile arthritis.

SYMPTOMS

The most common symptoms of JA include pain, stiffness, redness, swelling, and warmth in a joint. Over time, the bones around an infected joint may grow too quickly or too slowly. As a result, a child's arms and legs may be of different lengths. A common consequence of JA is the condition known as contracture. Contracture is a shortening of muscle that occurs when the muscle is not used. Contracture occurs in JA patients because they find it painful to move, so their muscles are not exercised normally.

Five types of JA have been identified. Each type has its own specific symptoms. These five types are:

• Pauciarticular JA. Pauciarticular (pronounced paw-see-ar-TIK-yoo-luhr) JA is the most common and least severe form of JA and affects about 40 percent to 60 percent of all JA patients. Pauciarticular JA usually occurs in only four joints: the knee, ankle, wrist, and/or elbow. It usually does not interfere with the patient's growth. Less than 15 percent of patients with this form of JA end up with deformed joints. Some children with the disorder have swelling in a joint without pain. Others develop an inflammation of the eye that can lead to blindness if left untreated. Many children with pauciarticular JA recover completely within a few years of diagnosis.
• Polyarticular JA. About 40 percent of all cases of JA are polyarticular (pronounced pol-ee-ar-TIK-yuh-luhr). It occurs more commonly among girls than boys. Polyarticular JA usually develops before the age of three or after the age of ten and affects five or more joints at the same time. It occurs most commonly in the small joints of both hands and both feet, but it can also develop in larger joints, such as the elbow or knee. If the condition occurs in both knees at once, the patient's legs may grow at different rates so that one leg becomes longer than the other.

About half of all patients with polyarticular JA have arthritis of the spine and/or hip. Many patients with the disorder also have more general symptoms, such as anemia (low red blood cell count; see anemias entry), decreased growth rate, poor appetite, low-grade fever, and a slight rash.

This form of JA is most severe when it occurs during early adolescence. In some cases, the disorder may be an early form of an adult disorder known as rheumatoid arthritis (see arthritis entry). The disorder can be very serious because it destroys and deforms the joints.

Systemic onset JA. Systemic onset JA is also called Still's disease after the doctor who first described it. It occurs in 10 percent to 20 percent of patients with JA and is equally common in boys and girls. The disorder is usually first seen between the ages of five and ten. The initial symptoms of systemic onset JA do not occur in the joints. Instead, they are general symptoms, such as high fever, rash, loss of appetite, and weight loss. More serious symptoms may also develop, including pericarditis (inflammation of the sac surrounding the heart; pronounced per-i-kar-DIE-tiss), pleuritis (inflammation of the tissue lining the lungs; pronounced ploor-I-tuhs), and myocarditis (inflammation of the heart muscle; pronounced my-o-kar-DIE-tiss).

Typical symptoms of arthritis affecting the joints usually develop later in systemic onset JA. They generally show up in the wrists and ankles. Many children go through regular cycles when their condition becomes worse and then better. They may also develop polyarticular JA.

Spondyloarthropathy. Spondyloarthropathy (pronounced SPON-duhlo-ar-THROP-uh-thee) is relatively rare. It occurs most commonly in boys older than eight. Arthritis develops first in the knees and ankles and then moves upward to include the hips and lower spine.

Psoriatic JA. Psoriatic (pronounced sore-ee-AT-ik) JA usually starts in fewer than four joints. However, it gradually spreads to include many joints, as in polyarticular JA. The hips, back, fingers, and toes are often affected. A skin condition known as psoriasis (pronounced suh-RIE-uh-sis) accompanies this form of JA. Psoriatic JA often becomes a serious, disabling problem.

DIAGNOSIS

Diagnosis is usually made on the basis of a patient's symptoms. Laboratory tests are often not very helpful because they do not show any indication of disease.

TREATMENT

The goal of treating JA is to decrease the inflammation in a joint. In this way, the patient retains better movement. Common medications used to reduce inflammation are the nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (pronounced i-byoo-PRO-fuhn, trade name Advil) and naproxen (pronounced nuh-PROKS-suhn, trade name Aleve). Steroid drugs can also be given by mouth or injection. Oral injections are helpful but have dangerous long-term side effects. Injections of steroids directly into a joint are often the best treatment.

Other drugs used to treat JA include methotrexate (pronounced methuh-TREK-sate), sulfasalazine (pronounced SULL-fuh-SAL-uh-zeen), penicillamine (pronounced pen-i-SIL-uh-meen), and hydroxychloroquine (pronounced hi-droks-ee-KLOR-uh-kween). Steroid eyedrops can be used to treat eye inflammations.

Physical therapy and exercise are often recommended to improve joint mobility and muscle strength. Occasionally, splints are used to rest painful joints and to prevent or improve deformed joints.

Alternative Treatment

Some practitioners recommend juice therapy for treating JA. Patients are encouraged to drink a mixture of fruit and vegetable juices, including carrots, celery, cabbage, cherries, lemons, beets, cucumbers, radishes, and garlic. Another alternative therapy is aromatherapy, in which the patient inhales vapors that include cypress, fennel, and lemon. Massage with oils such as rosemary, chamomile, camphor, juniper, and lavender can sometimes be helpful. Other types of therapy include acupuncture (a Chinese therapy that involves the use of fine needles) and acupressure (a Chinese therapy treatment during which pressure is applied to certain points in the body).

Some authorities believe that nutritional supplements can relieve the symptoms of JA. These supplements include large amounts of antioxidants (vitamins A, C, and E; zinc; and selenium) as well as B vitamins and minerals such as boron, copper, and manganese.

There is some evidence that JA can be caused by food allergies. Patients should identify any foods that increase their symptoms and exclude those foods from their diet.

PROGNOSIS

The prognosis for pauciarticular JA and spondyloarthropathy is quite good. It is not as good for polyarticular JA, which can sometimes lead to more serious forms of arthritis when the patient gets older, as well as to joint deformities. The prognosis for systemic onset JA depends on the organs affected. About 1 percent to 5 percent of all JA patients die of complications of the disorder, such as infection, inflammation of the heart, or kidney disease.

PREVENTION

Because so little is known about the causes of JA, there are no recommendations for avoiding the disorder.

FOR MORE INFORMATION

Books

Aldape, Virginia Tortorica. Nicole's Story: A Book About a Girl With Juvenile Rheumatoid Arthritis. Minneapolis, MN: Lerner Publications, 1996.

Organizations

American College of Rheumatology. 60 Executive Park South, Suite 150, Atlanta, GA 30329. (404) 633–1870. http://www.rheumatology.org.

Arthritis Foundation. 1330 West Peachtree Street, Atlanta, GA 30309. (404) 872–7100. http://www.arthritis.org.

National Institute of Arthritis and Musculoskeletal and Skin Diseases. http://www.nih.gov/niams.

Web sites

"Arthritis." [Online] http://arthritis.miningco.com (accessed on June 20, 1999).