Children Can Develop Juvenile Arthritis

Youngsters May Not Understand Their Pain

Young girl with doctor.
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When most people think of arthritis, they don't associate it with children. The most common misconception about arthritis is that it is an old person's disease. In reality, arthritis affects people of all ages, including about 300,000 American children.

In young people and children under the age of 16, arthritis is classified differently than in adults. The course of the disease in children is usually different than in adults.

Children experience different symptoms and generally have a more favorable prognosis.

Childhood arthritis is called juvenile arthritis or juvenile idiopathic arthritis. It is also referred to as juvenile rheumatoid arthritis (JRA), though that is an older term.

Juvenile Arthritis Subsets

For decades, juvenile arthritis was divided into three main subsets, each affecting different joints with a distinct pattern of symptoms:

  • polyarticular juvenile arthritis
  • pauciarticular juvenile arthritis
  • systemic juvenile arthritis

In 2001, The International League of Associations for Rheumatology (ILAR) divided juvenile arthritis into more subtypes, primarily for research purposes. TheĀ 7 Subtypes of Juvenile Idiopathic Arthritis will continue to evolve and expand as more is learned about juvenile idiopathic arthritis. To develop a basic understanding, let's first consider the original three subsets of juvenile arthritis.

Polyarticular Disease

Polyarticular disease is a disease of many joints. This type of juvenile arthritis affects more than five joints and is most similar to adult rheumatoid arthritis. Girls are twice as likely to develop polyarticular disease than boys. The joints are usually affected symmetrically (on both sides).

Often the small joints of the hands are affected, as well as other joints. Low-grade fever, weight loss, and anemia may occur, as well as growth problems in severe cases.

Most children with polyarticular disease are negative for rheumatoid factor and their prognosis is usually good. A minority of children who are positive for rheumatoid factor seem to be at greater risk for chronic, progressive destruction and joint damage.

Pauciarticular Disease

Pauciarticular disease is the type of juvenile arthritis that affects four or fewer joints. Most commonly affected are the knees, elbows, wrists, and ankles. The joints are usually affected asymmetrically (i.e., affected joint on one side of the body, not both). This is regarded as the most common type of juvenile arthritis and affects over 50% of children with the disease. Pauciarticular juvenile arthritis mostly affects girls. Those with pauciarticular disease usually have a positive antinuclear antibody (ANA) test and are prone to an inflammatory eye condition, iridocyclitis.

Children with pauciarticular juvenile arthritis generally do well. In the newer classification, this type of juvenile arthritis is referred to as oligoarticular juvenile idiopathic arthritis.

Systemic Disease

Systemic disease begins with generalized symptoms that affect internal organs and parts of the body other than joints. This form of juvenile arthritis is the least common and affects only about 10% of children with the disease. Systemic disease often begins with fevers which seem to come and go, lasting for weeks or months. A light-colored rash may exist on the thighs and chest. The child with systemic disease may exhibit:

  • signs of enlargement of the spleen and lymph nodes
  • inflammation of the heart muscle and surrounding tissues
  • a high white blood cell count
  • anemia
  • fatigue
  • weight loss

The prognosis of systemic disease is considered favorable. In 75% of cases, systemic disease subsides without long-term effects. In adults, this condition is called Adult Onset Still's Disease.

Observing Early Symptoms

Very young children may not realize what is wrong when they experience pain. Children may not know how or may not be able to express a complaint about the stiffness, achiness, and pain they are feeling. Those who are observed having trouble climbing steps, throwing a ball, opening a door, or just walking may be in need of a physical assessment by a physician. Parents and teachers need to be aware that arthritis affects children, too. Early diagnosis and proper treatment are essential.

Sources:

The Duke University Medical Center Book of Arthritis, by David S. Pisetsky, M.D, Ph.D.

Primer of the Rheumatic Diseases. Arthritis Foundation. Thirteenth Edition.

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