Juvenile Rheumatoid Arthritis

By Michael K. Davis, MD
July 31, 2009

Juvenile rheumatoid arthritis (JRA) is a disorder that causes chronic inflammation of the joints in children less than 16 years of age.  The cause of JRA is unknown, however it seems to be related to certain genes that disrupt the immune system, leading to inflammation (especially arthritis). 

Arthritis is defined as swelling or limitation of motion of the joint accompanied by heat, pain, and/or tenderness.  JRA is classified into 7 basic types depending on the number and location of joints involed and the involvement of other body parts.  The treatment of JRA in children involves limiting pain and the development of long-term damage. 

The first treatment for most children with JRA includes non-steroidal anti-inflammatory medicines (NSAID’s) such as ibuprofen.  Some children require treatment with corticosteroids or other medications that regulate or suppress the immune system.  Most children with JRA have symptems that are well-controlled with medications and have limited disability.

 

What is JRA?

Juvenile rheumatoid arthritis (JRA) is a disorder that causes inflammation of the joints that lasts more than 6 weeks.  While children and adults of all ages can develop arthritis, the term “JRA” is reserved for children that develop symptoms before 16 years of age.  Some children may have involvement of one joint (i.e., the knee) while others may have inflammation in several joints.  In some cases, JRA may lead to poor growth, eye inflammation and bone mineral loss.

 

What causes JRA?

The exact cause of JRA is unknown.  There seem to be several genes that make a child more likely to get JRA.  It is possible that a child with abnormal “JRA genes” may develop JRA after an infection or other environmental trigger.

 

Who gets JRA?

Up to 100,000 children in the United States have JRA.  Symptoms must begin before 16 years of age to be considered JRA.

 

 What are the symptoms of JRA?

• Arthritis (swelling, redness, pain, and warmth in a joint).  May affect a single joint or several joints.  The knee is the most common joint affected.  There may be mild or no pain.  Use of the joint may be avoided (i.e., limping) or the range of motion may be decreased.  Arthritis must last more than 6 weeks or more to be considered JRA.  Many viral infections may cause arthritis that looks like JRA, although arthritis due to viruses (i.e., toxic synovitis) lasts less than 6 weeks.
• Morning stiffness
•  Limping 

 

Sometimes present…

• Enthesitis (inflammation at the sites of attachment of ligament, tendon, or fascia to bone)
• Dactylitis (swelling of the fingers or toes)
• Lower back pain
• Nail pitting (small indentations in the finger or toe nails
• Psoriasis (large areas of skin scaling)
• Fever
• Rash
• Fatigue
• Malaise (a general sick feeling)
• Inflammation in or around other organs

 

How is JRA diagnosed?

There is no specific JRA test.  Your history and physical exam are key for the diagnosis.

 

Blood tests

• Erythrocyte sedimentation rate (ESR) – A general marker for inflammation.  Elevated in JRA.
• Hematocrit – Anemia may be present due to the effects of chronic inflammation.
• White blood count, platelets, ferritin – Other blood tests that may indirectly indicate inflammation.
• Anti-nuclear antibody (ANA) – A marker of an auto-immune process.  Often present in JRA.  Also present in some normal people.
• Rheumatoid factor – A marker for JRA.  May indicate a more aggrssive form of JRA.
• X-rays are often normal initially but may show bone damage in chronic or severe arthritis.

Imaging

How is JRA treated?

Different patients respond differently to different medications.  Some options include…

• Non-steroidal anti-inflammatory medicines (NSAID’s) such as ibuprofen or naproxen. 
• Corticosteroids taken as an oral medicine or injected into affected joints.
• Methotrexate is an immunomodulating medication.  Lab values must be monitored closely. 
• Anti-TNF therapy is given intraveneously or intramuscularly.
• Other medications are used to reduce inflammation, modulate or suppress the immune system.

 

A healthy diet with adequate calcium and vitamin D to minimize bone mineral loss.

 

Folate is given when methotrexate is used.

Physical therapy is often required to maintain good joint function and range of motion.

 

What happens with JRA long-term?

The future course of JRA depends on the type of JRA.  Many children with JRA will outgrow the disease.  Some forms of JRA persist into adulthood and some forms of JRA will be life-long.

 

What are the possible complications of JRA?

• Joint and cartilage damage
• Joint stiffness
• Poor growth
• Limb length differences
• Uveitis (a type of eye inflammation that can cause loss of vision if not detected early)
• Pericarditis (inflammation around the heart) in the systemic form of JRA
• Pleuritis (inflammation around the lungs) in the systemic form of JRA

 

Source: Dr. Tummy

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