Juvenile Arthritis - Symptoms

The most common symptoms of JA include pain, stiffness, redness, swelling, and warmth in a joint. Over time, the bones around an infected joint may grow too quickly or too slowly. As a result, a child's arms and legs may be of different lengths. A common consequence of JA is the condition known as contracture. Contracture is a shortening of muscle that occurs when the muscle is not used. Contracture occurs in JA patients because they find it painful to move, so their muscles are not exercised normally.

Five types of JA have been identified. Each type has its own specific symptoms. These five types are:

• Pauciarticular JA. Pauciarticular (pronounced paw-see-ar-TIK-yoo-luhr) JA is the most common and least severe form of JA and affects about 40 percent to 60 percent of all JA patients. Pauciarticular JA usually occurs in only four joints: the knee, ankle, wrist, and/or elbow. It usually does not interfere with the patient's growth. Less than 15 percent of patients with this form of JA end up with deformed joints. Some children with the disorder have swelling in a joint without pain. Others develop an inflammation of the eye that can lead to blindness if left untreated. Many children with pauciarticular JA recover completely within a few years of diagnosis.
• Polyarticular JA. About 40 percent of all cases of JA are polyarticular (pronounced pol-ee-ar-TIK-yuh-luhr). It occurs more commonly among girls than boys. Polyarticular JA usually develops before the age of three or after the age of ten and affects five or more joints at the same time. It occurs most commonly in the small joints of both hands and both feet, but it can also develop in larger joints, such as the elbow or knee. If the condition occurs in both knees at once, the patient's legs may grow at different rates so that one leg becomes longer than the other.

About half of all patients with polyarticular JA have arthritis of the spine and/or hip. Many patients with the disorder also have more general symptoms, such as anemia (low red blood cell count; see anemias entry), decreased growth rate, poor appetite, low-grade fever, and a slight rash.

This form of JA is most severe when it occurs during early adolescence. In some cases, the disorder may be an early form of an adult disorder known as rheumatoid arthritis (see arthritis entry). The disorder can be very serious because it destroys and deforms the joints.

Systemic onset JA. Systemic onset JA is also called Still's disease after the doctor who first described it. It occurs in 10 percent to 20 percent of patients with JA and is equally common in boys and girls. The disorder is usually first seen between the ages of five and ten. The initial symptoms of systemic onset JA do not occur in the joints. Instead, they are general symptoms, such as high fever, rash, loss of appetite, and weight loss. More serious symptoms may also develop, including pericarditis (inflammation of the sac surrounding the heart; pronounced per-i-kar-DIE-tiss), pleuritis (inflammation of the tissue lining the lungs; pronounced ploor-I-tuhs), and myocarditis (inflammation of the heart muscle; pronounced my-o-kar-DIE-tiss).

Typical symptoms of arthritis affecting the joints usually develop later in systemic onset JA. They generally show up in the wrists and ankles. Many children go through regular cycles when their condition becomes worse and then better. They may also develop polyarticular JA.

Spondyloarthropathy. Spondyloarthropathy (pronounced SPON-duhlo-ar-THROP-uh-thee) is relatively rare. It occurs most commonly in boys older than eight. Arthritis develops first in the knees and ankles and then moves upward to include the hips and lower spine.

Psoriatic JA. Psoriatic (pronounced sore-ee-AT-ik) JA usually starts in fewer than four joints. However, it gradually spreads to include many joints, as in polyarticular JA. The hips, back, fingers, and toes are often affected. A skin condition known as psoriasis (pronounced suh-RIE-uh-sis) accompanies this form of JA. Psoriatic JA often becomes a serious, disabling problem.