Paget's Disease

by Food and Drug Administration (FDA)

Something weighs heavily on Jan Brown's head every day. Something called Paget's disease of bone, and it affects her skull. She feels the effects constantly, like 5 pounds of pressure, she says.

"It's always there," the 57-year-old Rockville, Md., woman says. "I can feel it right now as I speak."

Sometimes she takes Tylenol (acetaminophen) for the pain.

Seventy-two-year-old Kenneth Halstead, of Raleigh, N.C., also has Paget's disease. It affects his skull, as well as his spine, hips, pelvis, and right leg. It's evident from his right leg, which is bowed. On his right foot, he wears a "built-up" shoe to compensate for the half an inch his leg has shrunk. He also wears a hearing aid.

A 78-year-old woman from Washington, D.C., who asked that her name not be used, also has the disease. She, too, wears a hearing aid, and her head is pushed forward and down, preventing her from tilting her head back to look up.

Paget's disease is the second most common bone disease in the United States. Osteoporosis is No. 1. Paget's disease can cause pain, deformities, hearing loss, and limits on activity. The disease, which affects people in different ways, also can cause arthritis and other serious consequences.

Many people may dismiss these disabilities as a natural part of aging. The average age of diagnosis is 58 (although the disease actually may begin much earlier). But the disease is treatable, and with newer drugs on the market — including two approved by the Food and Drug Administration in 1991 and 1995 — there is greater opportunity for patients with Paget's disease to find pain relief, limit the progression of their disease, and, in some cases, reverse bone damage.

The challenge now, experts say, is to identify patients early and, if feasible, start treatment promptly. It's estimated that 3 percent of the American population over 40 is affected. The problem is that many people with Paget's disease don't know they have it because often it develops without symptoms.

Bone Gone Awry

Paget's disease gets its name from Sir James Paget, an English doctor who served as surgeon to Queen Victoria. He first described the disease's characteristics in 1876.

Many years later, scientists realized Paget's disease is a disruption in the normal activity of bone tissue.

Bone is constantly being broken down by cells called osteoclasts and rebuilt by cells called osteoblasts. This is called bone turnover, and throughout the entire skeleton, this process is normally in precise balance.

In Paget's disease, the process goes awry. In discrete portions of bone, overly large osteoclasts dissolve bone too quickly — as much as 50 times faster than normal. Osteoblasts try to compensate for the increased pace by rapidly depositing new bone. But, in the hurried process, the newly deposited bone is loose and bulky in structure, rather than strong, compact, and neatly arranged.

Over time, pagetic bone becomes weak and soft and can easily bend, actually shortening the part of the body affected: for example, a leg or the spine. The bone may enlarge in diameter, though, and it can become painful and break easily.

Any bone can be affected, but the most common sites are the spine, skull, pelvis, and legs. Some patients may have only one affected bone, while others may have two or more. The disease usually does not spread to unaffected bones.

Common deformities include bowed legs, an enlarged head or pelvis, and a curved back. Pagetic bone can affect other parts of the body, causing added problems. For example, it can change bones around joints, causing arthritis. If in the skull and the temporal bone (the bone surrounding the inner ear), Paget's disease can affect hearing. When it affects the facial bones, it can cause dental problems.

Because of changes to the bone, pagetic bones often contain more blood vessels than normal, increasing blood flow to affected bones. Because the heart has to work harder to pump the extra blood, Paget's patients with heart disease may be at even greater risk for heart failure.

Paget's disease is rarely fatal. However, fewer than 1 percent of patients may develop osteosarcoma, a form of bone cancer, and other sarcomas. Most Paget's patients die from causes unrelated to Paget's disease.

Causes

No one knows what causes Paget's disease, although genetics may play a role. Several studies indicate that 15 to 30 percent of Paget's patients have family members with the disease. Those with a first-degree relative — parent, sibling or child — with Paget's disease are seven times more likely to develop the disease than those without an affected first-degree relative.

"It clearly runs in families," says Ethel Siris, M.D., an endocrinologist at Columbia University College of Physicians and Surgeons in New York City. She says the risk increases if the first-degree relative has more severe disease and an early age at diagnosis. Paget's disease is rarely diagnosed in people under 40, although there have been cases. Siris says she's treated patients in their late 20s and early 30s.

The family history related by several patients seems to bear out Siris' conclusions: Evelyn Nef, 83, of Washington, D.C., who was diagnosed with Paget's disease in 1962, says her brother and sister also suffer from the disease. Halstead, who was diagnosed in his 30s, says his two brothers have the disease and his mother, who is 102, was diagnosed three years ago.

About the Author

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