Common Complaints: Paget's disease

SIR JAMES PAGET described his disease in the middle of Queen Victoria's reign, when every adult wore a hat and people knew the size they needed for a close fit.

So it was natural to highlight a need for a larger size of hat as an early warning thatthe skull was growing larger. Nowadays the first symptom of Paget's disease is more likely to be pain in the back or hips, or even deafness.

Paget's disease, or osteitis deformans, is a change in the consistency of the bones. Bone is a living structure, constantly being absorbed and replaced, but in Paget's disease the process gets out of control and both reabsorption and replacement growth accelerate, with the new bone formed being thicker but spongier and so weaker. The disease is usually patchy - at least in its early stages - and the skull, spine, pelvis and leg bones are common first sites for attack.

As many as 3 per cent of people over 40 years old in Britain are affected, but fortunately most have no symptoms and are found to have the disease only if a bone X-ray is taken for some other reason. Within Britain, some parts of the country have higher rates of the disease than others, and within Europe there are even wider fluctuations, which has led to the suggestion that the disease may be due to some sort of infection, possibly with a virus.

The disease causes several types of health problems. The overgrowth of bone not only stretches the hat but also changes the appearance of the face, thickening the features, and may cause the legs to become bent or curved. The spongy bone may become distorted and so lead to, or worsen, arthritis in the spinal bones and around the hip joints. Fractures are common, even without any fall or other accident. Pressure on nerves by the growing bone commonly leads to deafness and headache and sometimes to weakness of the legs from pressure on the spinal cord. The blood flows rapidly through the spongy bone and the heart's work may be substantially increased. The most serious complication is a form of bone cancer, but this develops in fewer than one in every 100 people with the disease.

Most people found to have Paget's disease need no treatment. Persistent pain, symptoms due to pressure on nerves, or repeated fractures all indicate a need for something to be done, and there are now many different lines of drug treatment. If pain is the main problem the first step will be to suppress it with one of the non-steroidal anti-inflammatory drugs. Sodium fluoride decreases the activity of the disease, but the bone remains weak. The hormone calcitonin slows the reabsorption of bone; it is obtained from pigs and a synthetic version of the hormone is also used.

A newish group of drugs, the diphosphonates, also reduces the bone disease process. Another category of drugs is the anti-cancer agents which halt cell division and so slow the disease. Sometimes orthopaedic surgery, such as joint replacement, may be helpful.

As is always the case with a chronic disease with a large range of options, the best treatment is likely to come from a doctor with a special interest in the disease who has seen large numbers of patients and has

personal experience of all the available therapies. The newest remedies are not necessarily the best: aspirin is often extremely effective, especially if high doses can be taken without upsetting the stomach.