Juvenille Rheumatoid Arthritis (JRA), Part 1 — Introduction, incidence, and symptoms
What is JRA?
JRA is juvenile rheumatoid arthritis. There are over one hundred forms
of arthritis that children can get but JRA is the most common form of
childhood arthritis. The word arthritis means joint inflammation (swelling,
heat and/or pain in the joints). About 285,000 children in the United States are
diagnosed with arthritis. There are three major types of JRA:
- Polyarticular JRA,
which affects five or more joints
- Pauciarticular JRA, which affects four or
fewer joints
- systemic onset JRA, which also 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,
and a complete musculoskeletal exam assist in confirming the diagnosis.
A pediatric rheumatologist is a physician that specializes in treating
children with JRA.
Incidence and prevalence
Incidence of JRA has been estimated to be 10-20 cases per 100,000 children.
Prevalence data vary (11-83 cases per 100,000), depending upon the location
of the study. Pauciarticular and polyarticular disease occur more frequently
in girls, while both sexes are affected with equal frequency in systemic-onset
disease.
No recent studies have quantified mortality in JRA. However,
the mortality rate is less than 1% and is often associated with the evolution
of disease to manifestations of other rheumatic diseases, such as systemic
lupus erythematosus (SLE) or scleroderma. Such progression has been reported
to be associated with high titer antinuclear antibodies (ANA) at presentation
in some children.
Patients with JRA may experience complications specific to their disease
subset.
The most typical type of morbidity in patients with JRA relates
to adverse effects of medications, particularly NSAIDs. Abdominal pain
related to gastritis or ulcer disease, hepatotoxicity, and occasionally,
renal toxicity are sufficiently frequent to warrant routine laboratory
screening.
Significant psychologic morbidity (eg, situational depression, problems
functioning in school) can occur in all subtypes.
However, it is most
severe in children with polyarticular disease. Morbidity experienced in
problems with quality of life is being actively investigated. Such problems
may occur in children with all subtypes and may be the result of additional
factors, such as socioeconomic status and family problems.
Pauciarticular and polyarticular JRA tend to affect girls more often than
boys. Systemic-onset disease occurs with equal frequency in boys and girls.
Pauciarticular JRA tends to affect young children in early childhood.
Systemic-onset disease can also occur in early childhood. However, it
is sometimes observed in late childhood or early adolescence. Polyarticular
JRA can occur throughout childhood and adolescence. Rheumatoid factor–positive
disease, similar to rheumatoid arthritis in adults, is more often found
in adolescents.
Symptoms
The hallmark of JRA is joint pain and swelling. Children may be stiff
after they wake up in the morning and have difficulty getting ready for
school. They may complain about joint pain or stop doing activities such
as climbing stairs or shopping at the mall. Young children may refuse
to walk and want to be carried. Activities of daily living such as dressing
and eating may be difficult. They may lose muscle strength because of
pain in their joints, such as their hands.
The biggest school symptom
is a change in activity in Physical Education (PE) classes.
Fatigue is also common and children may
be less active at recess or PE or may rest on their desks in class.
Parents may notice they are going to bed earlier or taking naps after
school. Parents may 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 and may
have difficulty with joint pain and fatigue initially but have few symptoms
after management with appropriate medication.
Initially they may need
some accommodations but will function normally most of the time. Weather
changes, intercurrent illnesses, and overactivity may cause an increase
in joint symptoms temporarily. Children with severe disease may not have
all their symptoms controlled by medication and may have ongoing pain
and fatigue.
JRA, Part 1 — Introduction, incidence, and symptoms
For more information, please contact:
Kathy Davis, MSEd, PhD
kdavis2@kumc.edu
(913) 588-6305