The word "arthritis" means inflammation of a joint (or joints). Inflammation of a joint results in accumulation of inflammatory fluid inside the joint or in thickening of the lining of the joint (called the synovium), which in turn leads to swelling of the joint. If there is no swelling, at least two of the following three symptoms have to be present: pain or tenderness on movement of a joint, limitation of range of movement, and heat.
Although inflammation of a joint causes pain, pain in the joint is not always caused by inflammation. Therefore, just because a child has pain in a joint, it does not necessarily indicate arthritis, although arthritis is one of the major and most important causes of joint pain.
Arthritis may affect one or many joints. When it affects one joint, it's called monarticular arthritis. When it affects several joints, it's called polyarticular arthritis. When it occurs abruptly and with severe pain, heat, and an inability to move, it's called acute arthritis, and it often makes a physician suspect infection with bacteria (septic arthritis).
Arthritis may also come on gradually over several weeks, and last for weeks or months; this is called chronic arthritis. The causes of chronic arthritis are different from the causes of acute arthritis.
Signs and Symptoms
Below are some common symptoms of arthritis in children:
-Pain in joints
-Swelling of joints
-Inability to move the joint
-Holding the affected limb in one position
-Heat over the joint
-Stiffness of joints
-Irritability ( in infants)
-Crying on handling (in infants)
Associated signs and symptoms, such as fever rash, sores in the mouth, redness and watering of the eyes, if present, may help the physician determine the exact diagnosis of what disease condition is responsible for the arthritis.
As already pointed out, pain in a joint alone is not an indication of arthritis. The mistake of identifying a symptom (pain in a joint) with a disease (arthritis) leads to unnecessary tests, overdiagnosis, inappropriate treatment, and unnecessary parental anxiety. Based on a child's medical history and a careful physical examination, the physician has to: (1) diagnose whether or not arthritis is the cause of the child's symptom-complex, and then (2) consider which of several diseases is causing the arthritis.
There are several causes of arthritis. As already discussed, septic arthritis is caused by infection with bacteria. Many viral infections can cause acute cases of arthritis. Arthritis of rheumatic fever is often acute, affects many joints, and moves from one joint to another. Lyme disease can cause arthritis and is often intermittent. Rheumatoid arthritis in children is called Juvenile Rheumatoid Arthritis, is chronic, and is different in many ways from arthritis seen in adults.
Some common causes of arthritis in children include:
-Infection-related arthritis: (Septic arthritis, Viral arthritis, Lyme disease)
-Immune related arthritis:(Rheumatic fever, Serum Sickness, Kawasaki disease)
-Juvenile Rheumatoid Arthritis
-Systemic Lupus Erythematosus
Some conditions associated with pain in the joints or with aches and pains may look like arthritis -- but the actual problem may be something else, with some of the conditions being benign while others are serious. The following is a list of conditions that can "mimic" arthritis that the physician must be aware of when examining a child:
-Hypermobility of joints
-Slipped Capital Femoral Epiphysis
It is also important to remember that as part of normal growth, children often complain of pain in their arms and legs without suffering any limitation of normal activities (so called "growing pains"). And both children and adults with depression often complain of pain in various parts of the body.
These aches and pains may be generalized, or they may be localized, such as in the muscles, bones, or joints. In the medical literature, joint pain alone without inflammation is called arthralgia, a condition that requires proper attention, since several diseases are associated with it. A partial list of diseases associated with arthralgia is as follows:
-Excess physical activity
-Acute viral diseases (e.g., flu)
-Chronic diseases (e.g., diabetes, thyroid disease)
-Bone diseases (tumors)
-Neurological diseases (e.g., Guillain-Barre syndrome)
-Generalized malignancy (leukemia)
-Psychosocial problems ( school avoidance, family stress)
-Reactions to medications
-Lack of sleep
-Chronic Fatigue Syndrome
Given that it's impossible to do tests to exclude every one of these conditions, it becom`s clear why the physician has to evaluate each child's medical history, perform a careful physical examination, and think about the best possible explanation before ordering appropriate laboratory tests and/or imaging studies (plain x-rays, a CT scan, or an MRI).
It is important to remember that laboratory tests cannot differentiate between health and disease. The history and physical examination help the physician decide whether a given disease is -- or might -- be present. The tests are performed to confirm the presence of a suspected disease. Additional tests may then be performed to define the disease and also to exclude any conditions that can mimic the suspected disease.
Even after these steps have been taken, there are two frequent problems in the diagnosis of rheumatic diseases: 1. Rheumatic diseases (which include rheumatic fever, rheumatoid arthritis, and systemic lupus erythematosus) are like "first cousins" -- they strongly resemble each other, but with minor but crucial variations. 2. Since many of these diseases evolve over months and years, a physician may initially label a child as having one disease (e.g., juvenile rheumatoid arthritis) and later change the diagnosis to another one (e.g., psoriasis-related arthritis).
Treatment of arthritis will depend on what the physician has determined to be the actual cause of the arthritis. If the cause is a bacterium, such as staphylococcus or the organism that causes Lyme disease, the treatment will be an appropriate antibiotic. If the cause is rheumatic fever, the child will need penicillin to eradicate the streptococcal infection and a nonsteroidal anti-inflammatory drug (NSAID) to treat the arthritis.
Rheumatoid arthritis will require treatment with one of the nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (marketed as Advil, Motrin, etc.), and naprosyn (marketed as Aleve). If these do not work the physician may suggest adding other drugs such as methotrexate or a newer biological agent called "Enbrel." [Because of reports of serious, and sometimes fatal, infections in some patients using etanercept (Enbrel), the manufacturers Immunex Corporation and Wyeth-Ayerst Laboratories, at the FDA's request, have placed a boxed warning on the label. Patients should discuss with their physician their risk of infection while on, or before instituting, therapy with Enbrel.]
For children with rheumatoid arthritis, a physical therapy program is often needed to maintain the range of movement, relieve pain and stiffness, and maintain and improve function.
If there is infection of a joint, an orthopedic surgeon may be brought in (in addition to treatment with antibiotics) to remove as much of the fluid as possible. This is especially necessary if the infected joint is the hip. The child will be placed in a splint until the infection subsides and the pain brought under control. The child will require physical therapy throughout the period of treatment.
If the joint swelling and pain are due to leukemia, the child will be referred to an oncologist (a physician who specializes in leukemia and cancers), whereas a child with slipped capital femoral epiphysis should be cared for by an orthopedic surgeon.
In summary, treatment will be quite different for the many different conditions causing arthritis. That's why proper diagnosis is so critical before any treatment can be planned.