What is Paget's disease?
Paget's disease (osteitis deformans) is a chronic metabolic disorder of the bone. Bone is a living tissue that is constantly renewed by the body - old bone is destroyed and replaced by new bone. This process is known as remodelling. In Paget's disease, the remodelling process is affected and there is excessive and increased destruction of old bone tissue and increased and irregular generation of new bone tissue. This results in larger, weaker bones with an irregular structure.
The symptoms can vary greatly and in people with a mild form of the disease there may be no symptoms at all. Fortunately, only a small proportion of people with Paget's disease have the severe form which can cause multiple problems. The disease tends to occur in people over the age of 50.
Paget's disease is more common in the UK than anywhere else in the world, with an estimated 5 in 100 people over the age of 50 thought to be affected by it.
What are the symptoms of Paget's Disease?
As mentioned above, there may be no symptoms in mild forms of the disease. In severe cases, there may be intense pain. Deformities can occur as a result of the bones softening and enlarging. The bones most often affected are those of the skull, spine, pelvis, legs and collarbone. The spinal column may start to curve and the knees may bow. The skull may increase in size which can result in deafness, dizziness, tinnitus (noises in the ears) and disturbances of vision due to nerves being compressed by the increased pressure within the skull.
As the disease progresses, bone structure becomes weaker and increasingly fragile and fractures are a common complication. Arthritis can also develop.
The pain experienced by people with Paget's disease is usually bone pain in the affected areas but a person may also have headaches if the skull is affected.
What is the cause of Paget's Disease?
It is known that levels of an enzyme called alkaline phosphatase are elevated in the blood of people with Paget's disease. However, there is still no known reason for the development of this condition.
Are there any tests?
A diagnosis of Paget's disease can be confirmed by an x-ray or a bone scan. In many cases the disease is discovered during a routine x-ray for another reason, such as a fracture. A blood test may also be used to confirm the diagnosis as people with Paget's disease have increased levels of an enzyme called alkaline phosphatase in their blood.
What treatment is available?
In some people simple painkillers such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) (eg, ibuprofen) may be useful to relieve bone pain.
The bisphosphonates are a class of drugs that have been developed to treat Paget's and other bone diseases. These drugs act by changing the bone remodelling process back to normal, thereby increasing the strength of the bone structure. Bisphosphonates that may be given for Paget's disease include risedronate sodium tablets (Actonel®) or zoledronic acid intravenous infusion (Aclasta®).
A drug called calcitonin (salmon) may be prescribed if alternative treatments are ineffective or not tolerated, primarily to reduce bone pain. It also lowers calcium levels in the blood by reducing bone loss. It is given by subcutaneous or intramuscular injection. However, nowadays this treatment is not used very often.
If a joint has become damaged or deformed joint replacement surgery may be an option.
Further information available from:
The National Association for the Relief of Paget's Disease
323 Manchester Road
Tel: 0161 799 4646
Arthritis Research UK
St Mary's Court
St Mary's Gate
Tel: 0300 790 0400
Fact sheet provided by MIMS
Date last reviewed: December 2008
What is Paget's disease?