Skip to Main Content

++

Juvenile idiopathic arthritis (JIA) refers to a group of disorders that are a major cause of chronic arthritis in children. It is the most common chronic rheumatic disease of childhood and can be a significant cause of both short-term and long-term disability. In the United States, approximately 294,000 children younger than 18 years have arthritis or other rheumatic conditions.

++

JIA is relatively common compared to other chronic diseases of childhood. There are as many children with juvenile-onset diabetes as there are those with juvenile-onset arthritis, and there are 10 times as many children with arthritis as there are children affected with muscular dystrophy.

++

Essentials of Diagnosis

++

  • Six weeks or more of persistent joint swelling, and the exclusion of other causes of arthritis in childhood.
  • There is no specific laboratory test that either confirms or excludes JIA.
  • The type of JIA is determined by the age of the child at onset of symptoms; the number and type of joints involved; the presence of extra-articular symptoms, such as rash, fever, and iritis; and the course of the illness during the first 6 months after the diagnosis is confirmed.
  • Significant complications, including macrophage activation syndrome (MAS), contractures, growth retardation, and visual loss, can be avoided by prompt diagnosis and treatment.

++

According to the International League Against Rheumatism, the types of JIA can be classified as oligoarticular, polyarticular (including seropositive and seronegative), systemic onset (SOJIA), psoriatic, enthesitis-related, and undifferentiated. The different subtypes of JIA are mainly determined by the pattern of joint involvement at the onset of the illness.

++

The subtypes of JIA are identified and classified based on the following factors: age at onset, number of joints involved initially, rheumatoid factor status, and associated extra-articular symptoms (Table 20–1). Identification of the correct subtype helps guide appropriate therapy and determine prognosis.

++
Table Graphic Jump Location
Table 20–1. Comparing the Features of the Subgroups of Juvenile Idiopathic Arthritis.

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.