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Arthritis



Arthritis is a term that refers to the inflammation of joints (the point where the ends of two bones meet each other). Upwards of 43 million American adults and children (1 out of every 6 citizens) have some form of the more than 100 different types of arthritis.



Inflammation is a reaction of the body to injury. Excess fluid is directed to the affected area, which produces swelling. The fluid is meant to aid the healing process, and is temporary for many injuries. However, in arthritis, the constant or recurring inflammation causes tenderness and stiffness that is debilitating over long periods of time.

In a typical joint, the ends of the bones are covered with a smooth material called cartilage. The cartilage allows the bones to move smoothly against each other. A joint is also wrapped in a network called the synovium. Fluid within the synovium (synovial fluid) helps ease the friction of bones rubbing against each other. Finally, the joint is supported and movement is possible because of ligaments, muscles, and tendons that attach to various regions of the joint. All of these components can be subject to arthritic inflammation.

The two most common types of arthritis are osteoarthritis and rheumatoid arthritis. Osteoarthritis is the gradual wearing away of the cartilage. This commonly occurs due to overuse of the joint, or because of an injury such as a fracture. As such, osteoarthritis is associated more with adults than with children or youth.

In rheumatoid arthritis, the synovium surrounding a joint becomes inflamed. Also, the bodies' own immune A close-up of a hand deformed by rheumatoid arthritis; the knuckles are swollen and reddened and the fingers curve away from the thumb. The ends of the middle fingers are swollen with cartilage accretion (called Heberden's nodes) that are an indication of osteoarthritis. Science Photo Library, National Audubon Society Collection/Photo Researchers, Inc. Reproduced by permission. The progression of osteoarthritis. Illustration by Hans & Cassidy. Courtesy of Gale Group.


system begins to attack and destroy the surface of the joint. This "self against self" immune reaction is typical of autoimmune diseases or conditions like rheumatoid arthritis. Both adults and children are susceptible to rheumatoid arthritis.

The first line of drug treatment for osteoarthritis, as well as other types of arthritis, is nonsteroidal anti-inflammatory agents (NSAIDs), including aspirin and medicines that are closely related to aspirin. Some NSAIDs are sold over-the-counter. But those having more potent dosages are sold only by prescription and have to be monitored carefully to avoid adverse side effects.

A second line of drug treatment involving corticosteroids is often needed for treatment of rheumatoid arthritis and other forms of the disease. Corticosteroids are used to reduce inflammation. These drugs, such as cortisone, simulate hydrocortisone, a natural chemical produced in the adrenal cortex. The function of compounds like corticosteroids is to try to slow the disease down or make it go into remission. This is done by suppressing the immune response that is key to the damage caused by rheumatoid arthritis.

The length of treatment can range from several days to years. Taken either as a pill or through injection, dosages vary according to the type of arthritis and the needs of the individual. Corticosteroids are used for both osteoarthritis and rheumatoid arthritis. These medicines are injected into a specific site, such as a finger joint or the knee, for quick relief from pain and inflammation. In addition to blocking prostaglandin production, they also reduce the amount of white blood cells that enter into the damaged area of the joint. Though aspirin and the other NSAIDs all work the same way to suppress prostaglandin production in the body, there are major differences in the way individuals will respond to particular NSAIDs.

Stomach bleeding and irritation of the gastrointestinal tract are the two major drawbacks of long-term aspirin and the other NSAID therapy. A newer form of NSAIDs called COX-2 inhibitors reduce the production of an enzyme that stimulates the immune response, thereby relieving arthritic inflammation, without blocking the enzyme that protects the stomach lining, thereby reducing stomach irritation. Acetaminophen relieves pain without stomach irritation, but it is not an anti-inflammatory, nor does it reduce the swelling that accompanies arthritis. Because suppression of the immune system can leave someone vulnerable to other infections, and because steroid compounds can have unwanted side effects that are more severe than those produced by the NSAIDs, the use of corticosteroids and other similarly-acting compounds to treat arthritis must be monitored under a physician's care.

Resources

Books

Mayo Foundation. Mayo Clinic on Arthritis Rochester, MN: Mayo Foundation for medical Education & Research, 1999.

Trien, S.F., and D.S. Pisetsky. The Duke University Medical Center Book of Arthritis. New York: Fawcett, 1995.


Organizations

Arthritis Foundation. PO Box 7669, Atlanta, GA 30357-0669. (800) 283-7800. <http://www.arthritis.org>.

Bryan Hoyle

KEY TERMS

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Anti-inflammatories

—Drugs that counteract inflammation. Corticosteroids and non-steroidal anti-inflammatory agents (NSAIDs) that reduce inflammation are used in the treatment of arthritis.

Cartilage

—The tissue that surrounds a joint and degenerates in osteoarthritis.

Synovial fluid

—Thick, clear, and viscous fluid that is found in bone joints, and is used to identify different types of arthritic conditions.

Additional topics

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