Juvenile idiopathic arthritis (JIA), also known as juvenile rheumatoid arthritis, is the most common type of arthritis in children under the age of 16. It causes joint inflammation and stiffness for more than six weeks, which leads to redness, swelling, warmth, and soreness in the joints. The disease can affect any joint and the inflammation can limit the mobility of affected joints.
Juvenile idiopathic arthritis is an autoimmune disorder, which means that it is caused by the body’s immune system, because it wrongly identifies some of its own cells and tissues as being foreign. This is why the body’s immune system starts attacking healthy cells and tissues, causing inflammation, characterized by redness, heat, pain and swelling.
One of the most common symptoms of juvenile idiopathic arthritis is pain. Although your child might not complain about any sort of joint pain, you may notice that he limps, this happening more often in the morning or after a nap.
Another noticeable symptom is joint swelling. Swelling of the joints is common, but you will be able to notice it first in larger joints such as the knee, making it a bit hard to spot early.
If your child seems clumsier than usual, especially in the morning or after naps, he most likely suffers from stiffness, which is another common symptom of the disease.
Studies haven’t found the cause for developing JIA yet, although they suspect two major causes. The first reason for developing JIA involves something in the child’s genetic makeup, giving him a tendency to develop the disease. The other cause researches suspect to be responsible for developing JIA is an environmental factor such as a virus that triggers development of the disease.
Types of JIA
Polyarticular. This type of disease appears in 30% of all children who suffer from JIA. This type of disease normally affects the small joints, but it can also affect large joints. Polyarticular JIA is a symmetrical disease, which means that it affects the same joints on both sides of the body. Some of the children suffering from polyarticular JIA have an antibody in their blood called rheumatoid factor, which makes the disease more severe, its symptoms being similar to adult rheumatoid arthritis.
Systemic. The systemic form of JIA is characterized by joint swelling, fever and a light pink rash. This form of disease may also affect internal organs such as the heart, liver, spleen and lymph nodes. Systemic JIA usually affects 20% of the children suffering from JIA. Most, if not all of the children suffering from this type of JIA, test negative for rheumatoid factor and antinuclear antibodies (ANA).
Pauciarticular. This is the most common form of JIA, with half of the children suffering from JIA developing it. The disease affects large joints such as the knees. Pauciarticular JIA is most likely to be developed by girls with age under 8. 20-30% of the children with pauciarticular JIA suffer from eye disease. Many of the children who suffer from pauciarticular JIA tend to outgrow arthritis by adulthood, but the eye problems may persist.
If your child suffers from any of these symptoms, you should get him checked by a doctor to make sure he is healthy. If not you should start treating him as soon as possible to avoid or prevent other health complications.