About 1 out of 1,000 children have
juvenile rheumatoid arthritis (JRA).1 There are three types of juvenile rheumatoid arthritis.
Pauciarticular JRA (also known as oligoarthritis) and
polyarticular JRA (also known as polyarthritis) are
most common in girls.
Systemic JRA is equally common in boys and
girls.2
The three types of JRA affect
children at the following rates:3
- About 60% of all children with JRA have
pauciarticular symptoms during the first 6 months. While as many as 1 out of 5
of these children goes on to develop polyarticular symptoms, most continue to
have less than 4 joints affected over time.4
- About 30% of all children with JRA have
polyarticular symptoms.
- About 10% of all children with JRA have
systemic symptoms.
Juvenile rheumatoid arthritis can occur at higher rates among
certain ethnic groups and in some geographic areas. Environmental and genetic
factors are thought to be responsible, though researchers have yet to confirm
this theory.4