Juvenile arthiritis more prevalent than ever

Arthritis is an inflammation of the joints, meaning that the joints get swollen, warm, and painful. It may be short-term — lasting for just a few weeks or months, then going away forever — or it can be chronic and last for months or years. In about half of cases, it can last a lifetime.

The most prevalent form of juvenile arthritis is juvenile idiopathic arthritis (JIA) (also known as juvenile rheumatoid arthritis, or JRA). It is very different from adult rheumatoid arthritis.

What Causes JIA?

It's not known exactly what causes JIA in kids. Research indicates that it is an autoimmune disease. In autoimmune diseases, white blood cells can't tell the difference between the body's own healthy cells and germs like bacteria and viruses. The immune system, which is supposed to protect the body from these harmful invaders, instead releases chemicals that can damage healthy tissues and cause inflammation and pain.

To effectively manage and minimize the effects of arthritis, an early and accurate diagnosis is essential. By understanding the symptoms and characteristics of each type of JIA, you can help your child maintain an active, productive lifestyle.

Types of JIA

JIA usually appears in kids between 6 months and 16 years old. The first signs often are joint pain or swelling or warm joints. Many rheumatologists (doctors specializing in joint disorders) find that the greater the number of joints affected, the more severe the disease and the less likely that the symptoms will eventually go into total remission. Remission is a medical term for temporary or permanent recovery.

There are seven types of JIA:

1. Systemic JIA. Affects the whole body. Symptoms include high fevers that often increase in the evenings and then may suddenly drop to normal. During the onset of fever, the child may feel very ill, appear pale, or develop a rash. The rash may suddenly disappear and then quickly appear again. The spleen and lymph nodes might become enlarged. Eventually many of the body's joints are affected by swelling, pain, and stiffness. Rashes may suddenly appear and disappear, developing in one area and then another. High fevers that tend to increase in the evenings and disappear are characteristic of systemic JIA

2. Oligoarthritis. Affects four or fewer joints, often the knee or ankle. Symptoms include pain, stiffness, or swelling in the joints. The two types of oligoarthritis, persistent and extended, are determined by how many joints are ultimately involved.

3. Polyarticular arthritis, rheumatoid factor negative. About 1 in 4 kids and teens with JIA have polyarthritis, which affects more girls than boys. Symptoms include swelling or pain in five or more joints. The small joints of the hands are affected as well as the weight-bearing joints like the knees, hips, ankles, feet, and neck. A low-grade fever also might develop, as well as bumps or nodules in areas of the body subjected to pressure from sitting or leaning.

4. Polyarticular arthritis, rheumatoid factor positive. This type of JIA behaves the most like adult rheumatoid arthritis, and kids who have it have a protein called rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP antibody) in their blood. Kids with polarticular JIA are at a higher risk of joint damage with erosions than in the other forms of JIA.

5. Psoriatic arthritis. Kids with this also have the psoriasis rash (a scaly red rash that can start behind the ears, on the eyelids, elbows, knees, or scalp) themselves or a close relative with psoriasis. Their fingernails and toenails might be affected by the condition.

6. Enthesitis-related arthritis. This type of arthritis often affects the legs and spine. Kids also might have inflammation at the entheses – areas where tendons join bones (where the Achilles tendon attaches to the back of the heel). Enthesitis-related arthritis includes a special group call juvenile ankylosing spondylitis (where joints of the low back are inflamed) and arthritis associated with inflammatory bowel disease (Crohn's disease and ulcerative colitis).

7. Undifferentiated arthritis. Arthritis that doesn't fit into any of the above categories or fits into more than one of the categories.

The first signs of arthritis, which can be subtle or obvious, include limping or a sore wrist, finger, or knee. Joints may suddenly swell and remain enlarged. Stiffness in the neck, hips, or other joints also can occur.

Inflammation of the iris (the colored area of the eye) may happen with or without active joint symptoms in any type of JIA. This inflammation, more likely to happen in girls than boys, is called iridocyclitis, iritis, or uveitis. Kids and teens with JIA should see an ophthalmologist (an eye doctor) regularly to check for this.

Diagnosis

To diagnose JIA, the doctor will take ask you questions about your child’s symptoms, find out whether other family members have had similar problems, and do a thorough physical examination. The doctor may order X-rays or blood tests to rule out other conditions or infections, such as Lyme disease, that may cause similar symptoms or occur along with the arthritis.

Other tests may include:

· CBC (complete blood count), a common blood test that checks all the basic cell types in blood, including red blood cells, white blood cells, and platelets. Knowing the amount and appearance of each cell type in a person’s blood can help doctors identify many medical conditions.

· Blood culture, a test to detect bacteria that cause infections in the bloodstream.

· Bone marrow biopsy, a test that allows doctors to look at blood where it's formed (in the bone marrow) to look for conditions such as leukemia.

· Erythrocyte sedimentation rate, which checks how rapidly red blood cells settle to the bottom of a test tube. This rate often increases in people when inflammation is occurring in the body.

· C-reactive protein (CRP) is a protein that the liver releases into the blood at the start of infection or inflammation; this level can rise if a person is having an arthritis flare-up.

· A test for rheumatoid factor (RF) and cyclic citrullinated peptide antibody (CCP), substances made in the blood of children with some forms of JIA. But it's found more often in adults with rheumatoid arthritis.

· ANA (antinuclear antibody), a blood test to detect autoimmune diseases. It's also useful in predicting which kids are likely to have eye disease with JIA.

· X-rays of the affected joints, and sometimes an MRI, to detect changes in bone and joints to evaluate the causes of unexplained bone and joint pain. In some cases, doctors may do a test called a bone scan.

In some cases, the doctor may want an orthopedic surgeon to examine your child's joints and take samples of joint fluid or synovium (the lining of the joints) for examination and testing.

Source: kidshealth.org