Of more than 100 different kinds of arthritis, these are the most common:
In a normal joint (where two bones come together), the muscle, bursa and tendon support the bone and aid movement. The synovial membrane (an inner lining) releases a slippery fluid into the joint space. Cartilage covers the bone ends, absorbing shocks and keeping the bones from rubbing together when the joint moves.
Also called degenerative arthritis. Occurs when the cushioning cartilage in a joint breaks down. Commonly affects feet, knees, hips, and fingers. Affects 16 million Americans, mostly 45 and older. About half of those 65 and older have this form. In osteoarthritis, cartilage breaks down and the bones rub together. The joint then loses shape and alignment. Bone ends thicken, forming spurs (bony growths). Bits of cartilage or bone float in the joint space.
In rheumatoid arthritis, inflammation accompanies thickening of the synovial membrane or joint lining, causing the whole joint to look swollen due to swelling in the joint capsule. The inflamed joint lining enters and damages bone and cartilage, and inflammatory cells release an enzyme that gradually digests bone and cartilage. Space between joints diminishes, and the joint loses shape and alignment. Immune system attacks the lining, or synovial membrane, of the joints. Involves the whole body, and may also cause fatigue, weight loss and anemia, and affect the lungs, heart and eyes. Affects about 2.1 million Americans, three times more women than men.
Causes sudden, severe attacks, usually in the big toe, but any joint can be affected. A metabolic disorder in which uric acid builds up in the blood and crystals form in joints and other places. Drugs and attention to diet can control gout. Affects about 1 million Americans (70 to 80 percent men), with first attack starting between 40 and 50 years of age. (See “Getting to Know Gout,” FDA Consumer, March 1995.)
A chronic inflammatory disease of the spine that can result in fused vertebrae and rigid spine. Often milder and harder to diagnose in women. Most people with the disease also have a genetic marker known as HLA-B27. Affects about 318,000 Americans, usually men between the ages of 16 and 35.
The most common form is juvenile rheumatoid arthritis. Arthritis diagnosis, treatment, and disease characteristics are different in children and adults. Some children recover completely; others remain affected throughout their lives. Affects about 200,000 Americans.
Bone and other joint tissues become inflamed, and, like rheumatoid arthritis, it can affect the whole body. Affects about 5 percent of people with psoriasis, a chronic skin disease. Likely to affect fingers or spine. Symptoms are mild in most people but can be quite severe. Affects about 160,000 Americans.
Systemic Lupus Erythematosus
Involves skin, joints, muscles, and sometimes internal organs. Symptoms usually appear in women of childbearing age but can occur in anyone at any age. Also called lupus or SLE, it can be mild or life threatening. Affects at least 131,000 Americans, nine to ten times as many women as men.
Arthritis can develop as a result of an infection. For example, bacteria that cause gonorrhea or Lyme disease can cause arthritis. Infectious arthritis can cause serious damage, but usually clears up completely with antibiotics. Scleroderma is a systemic disease that involves the skin, but may include problems with blood vessels, joints, and internal organs. Fibromyalgia syndrome is a soft-tissue rheumatism that doesn’t lead to joint deformity, but affects an estimated 5 million Americans, mostly women.
Source: The Food and Drug Administration
This article originally appeared in the March 1996 “FDA Consumer.”
The version below is from a reprint of the original article
and contains revisions made in December 1996 and June 1997.