Physical injuries and illnesses such as Lyme disease can mimic JRA. Many viral infections can cause self-limiting (going away on its own) arthritis. If the arthritis has not cleared within 6 weeks, your child's doctor may refer you to a rheumatologist or other specialist.
The first signs of arthritis may be subtle or obvious. Signs may include limping or a sore wrist, finger, or knee. Joints may suddenly swell and remain enlarged. Stiffness in the neck, hips, or other joints can also occur. Rashes may suddenly appear and disappear, developing in one area and then another. High fevers that tend to spike in the evenings and suddenly disappear are characteristic of systemic JRA.
Consult your child's doctor if any of these symptoms occur. Determining if your child has JRA starts with taking a detailed medical history and a thorough physical examination. Your child's doctor may take X-rays or perform blood tests to exclude other conditions that can mimic JRA. On some occasions, your child's doctor may want an orthopedic surgeon to examine your child's joints and take samples of joint fluid or the lining of the joints, for examination and testing.