Juvenile Idiopathic Arthritis

JIA is the most common type of arthritis in children under the age of 17. About one in every 1,000 children have some form of JIA, so there are many more common causes of pain in children than JIA. Pain without swelling is often from a cause other than inflammation.

Symptoms of JIA include:

• Joint stiffness in the morning
• Pain in the joints
• Swelling in the joints
• Difficulty with range of motion
• Recurrent fever
• Rash
• Abdominal pain

Some children have JIA symptoms for only a couple of months, while others may have symptoms that return throughout their lives.

Diagnosis of Juvenile Idiopathic Arthritis

For the pediatric rheumatologist to make an accurate diagnosis of JIA, your child must have consistent symptoms for at least six weeks with no other physical cause(s). This is because JIA cannot be diagnosed using blood tests, biopsies or X-rays—the diagnosis is based only on the symptoms and a physical exam.

However, the pediatric rheumatologist may also want to run certain blood tests to determine if your child has other conditions that often can look like JIA. These tests may include:

• Antinuclear antibody test. This blood test can check for the presence of antibodies that react to DNA, RNA or the proteins that are stored in the nucleus of a cell. If those antibodies are there, they can help the doctor determine your child’s risk of developing uveitis (inflammation of the middle layer of the eye), which is common with JIA.
• Complete blood count (CBC). Your child’s blood count may be assessed using a CBC blood test. A CBC measures your child’s red blood cells, white blood cells and platelets. If any of these levels are abnormal, your child may have a disorder other than arthritis. A CBC may also reveal anemia (low red blood cells) related to a chronic inflammation if the arthritis is particularly active.
• Erythrocyte sedimentation rate (ESR). Also called “sed rate,” this blood test can help the doctor determine if your child’s body has inflammatory activity.

Your child’s doctor will also likely run tests to check for other conditions that can appear to be JIA (such as Lyme disease or celiac disease), so they can be eliminated from the list of possible diagnoses.