Juvenile Rheumatoid Arthritis (JRA), Part 1 — Introduction, Incidence, Morbidity and Symptoms

What is JRA?

There are over one hundred forms of arthritis that can affect children, but JRA (juvenile rheumatoid arthritis, aka juvenile idiopathic arthritis or JIA) is the most common form of childhood arthritis. The word "arthritis" means joint inflammation, and includes swelling, heat and pain. About 285,000 children in the U.S. currently have arthritis. There are three major types of JRA:

  • polyarticular (PAH’-lee-ar-ti’-kyoo-lur) JRA, which affects five or more joints
  • pauciarticular (PAW’-see-ar-ti’-kyoo-lur) JRA, which affects fewer than five joints
  • systemic-onset JRA, which includes a high fever and characteristic rash

There is no single test to diagnose JRA, and the cause of JRA is still unknown. The diagnosis is determined by the presence of active arthritis in one or more joints for at least six weeks after other conditions have been ruled out. A thorough history, laboratory studies (including blood tests and urine analysis), and a complete musculoskeletal exam help the doctor make the diagnosis. Consultation with a pediatric rheumatologist, a physician that specializes in the treatment of children with arthritis, is recommended.

Incidence

The annual incidence of JRA has been estimated to be between 10 and 20 cases per 100,000 children. Pauciarticular and polyarticular disease occur more frequently in girls, while both genders are affected equally in systemic-onset disease. Polyarticular JRA can occur throughout childhood and adolescence. Rheumatoid factor–positive disease, similar to rheumatoid arthritis in adults, is more common in adolescents.

Mortality and morbidity

No recent studies have quantified mortality in JRA. However, the mortality rate generally is estimated to be less than 1 percent annually. Rarely, JRA may change to another kind of rheumatic disease, such as systemic lupus erythematosus (lupus, or SLE) or scleroderma. Patients with JRA may experience complications related to the specific type of disease that they have.

Most complications seen in patients with JRA relate to the side effects of the medications used to treat the disease, commonly the nonsteroidal anti-inflammatory drugs (NSAIDs). Abdominal pain may be related to gastritis or ulcer disease. Also, hepatotoxicity (liver damage) and renal toxicity (kidney damage) occur often enough that routine laboratory tests are done to make sure these side effects are not missed. Significant psychological morbidity (e.g., situational depression and difficulty in school) can occur in children who have all subtypes of JRA. However, it is most severe among those with polyarticular disease. Morbidity experienced as problems with quality of life may occur in children with all JRA subtypes, and may be compounded by additional factors, such as socioeconomic status and family problems.

Symptoms

The most common symptoms of JRA are joint pain and swelling. A child might be stiff upon waking in the morning and have difficulty getting ready for school. Complaints about joint pain can become prevalent, forcing the child to stop activities such shopping at the mall. A very young child might even refuse to walk and demand to be carried. Activities of daily living, such as dressing and eating, may become difficult. A child may also appear to lose muscle strength due to the joint pain.

The biggest symptom at school is a change in activity during physical education (PE) classes. Fatigue is also common, and can cause the child to be less active and to rest in the classroom. Parents might notice the child going to bed early and taking naps after school. Parents may also notice swelling in one or more joints.

The signs and symptoms of JRA vary from child to child, from day to day, and even throughout the same day. Most children have mild JRA. They may have difficulty with joint pain and fatigue immediately after diagnosis, but will have few symptoms when started on appropriate medication.

Children with JRA may need some accommodations initially, but most will continue to attend school and enjoy normal activities. Weather changes, other illnesses (especially viral infections such as colds or flu), and overactivity can increase symptoms temporarily. A child with severe disease, or whose symptoms do not respond adequately to medications, could have ongoing pain and fatigue.


For more information, see:

Part 2 — Treatment, Restrictions and Implications for School

Arthritis Foundation

P.O. Box 7669
Atlanta, GA 30357-0669
800-283-7800

Information about children and adolescents with arthritis.

US Bone and Joint Foundation (USBJD)

Information about pediatric arthritis.

Contributed by:

Carol Lindsley, MD
Professor
Division Chief, Pediatric Rheumatology
Department of Pediatrics
University of Kansas Medical Center

Kathy Davis, MSEd, PhD
Associate Professor
Project Director, Connected Kansas Kids
Director, KU Kids Healing Place
University of Kansas Medical Center