Paget's disease of bone

Bone is renewed throughout life: old bone is broken down and new bone laid in its place, the two kept in balance. In Paget's disease the cells that break bone down grow larger and far more active in one or more areas, and new bone is laid down fast in response, but it comes out larger, weaker and less orderly. What sets this off is not fully known. Genes play a large part, and the condition often runs in families, so tell your doctor if anyone in your family has had it; something in the environment may also be involved. It grows more frequent with age and seldom appears before 50, men have it slightly more often than women, and it tends to settle in particular bones, the pelvis, spine, skull and leg bones most of all, rather than spreading through the skeleton.

Plenty of people with Paget's disease feel nothing of it at all. When it does cause symptoms, they can include:

• Pain in an affected bone, often a dull, deep ache that is there most of the time and worse at night
• Skin that feels warm over the affected bone
• A bone that changes shape, or a leg that bows
• An aching joint beside the affected bone, where wear can set in, as our osteoarthritis guide describes
• Where enlarged bone presses on a nerve, pain that travels down a leg, numbness or tingling, or trouble with balance
• Where the skull is affected, headaches, ringing in the ears or a loss of hearing

A raised alkaline phosphatase, a bone enzyme, on a blood test is often the first hint, or else a change noticed on an X-ray taken for something unrelated. Imaging confirms it, and a radionuclide bone scan shows which bones are involved; it is a different test from the DEXA scan used for osteoporosis. The assessment also judges whether any affected bone is a problem now or could become one.

Treatment is not always needed, especially when there are no symptoms and no bone is at risk. When it is, bisphosphonates are the mainstay: they rein in the overactive turnover, usually given as one drip of zoledronic acid in a hospital clinic, and two months of risedronate tablets is another choice. Each tablet is taken on an empty stomach with a full glass of plain water, at least 30 minutes before food, any other drink and other medicines or supplements, calcium among them, so that it is absorbed, and you stay upright for at least 30 minutes after it, since such tablets can irritate the food pipe. Calcium and vitamin D are measured first and topped up as needed, since enough vitamin D before a drip makes a fall in calcium afterwards less likely. A later blood test of alkaline phosphatase shows how the bone has answered, yet the point of treating is to ease symptoms; returning the figure to normal is not the goal. Before a zoledronic acid drip, tell the doctor if you have atrial fibrillation (a fast and irregular heartbeat) or a raised risk of it. After the first drip, flu-like aches and a fever for a day or two are common, and they usually settle with paracetamol or ibuprofen; a fever that lasts beyond a few days, or climbs, is for your GP or NHS 111 the same day, as When to seek help says. If you can, finish any major dental work before starting a bisphosphonate, and tell your dentist that you are having, or have had, one.

Pain the bisphosphonate does not settle, especially from wear in a nearby joint, is eased with painkillers such as paracetamol or a stronger one containing codeine. An anti-inflammatory tablet (an NSAID) such as ibuprofen can help too, taken at the smallest dose that helps for the shortest time, and its use is best talked over with your doctor, especially if you have had a stomach ulcer, asthma, or heart, liver or kidney problems. Physiotherapy, a walking stick or shoe inserts can help too, and an operation is sometimes needed for a break, a badly worn joint, a marked bend in a bone or a nerve under pressure. You and Dr Borukhson settle the plan together.

Many people with Paget's disease never have symptoms or complications from it. Some everyday steps make a difference.

• Get enough calcium and vitamin D, from food and from supplements if you are advised to take them; your bones and your treatment both depend on them.
• Keep moving: walking and other weight-bearing exercise help keep bone and muscle strong, though a leg or spine affected by Paget's may call for a change of activity, so check first.
• Keep your appointments for blood tests and check-ups, which show how the affected bone is doing and how it has answered treatment.
• Look after the joints next to an affected bone, since wear is more likely to develop in them over the years; if it does, staying a healthy weight and strengthening the muscles around the joint can ease the pain.

Paget's disease overlaps with bone health in general, so your assessment also looks out for osteoporosis and other metabolic bone disease.

Most changes in Paget's disease come on slowly, often over years, and can wait for a routine review. The ones that cannot are listed here, each with where to go.

Treat any of these as a 999 or A&E emergency: call 999 and do not drive yourself to A&E.

• Numbness or tingling around the back passage, genitals or inner thighs, new difficulty passing urine or controlling your bladder or bowels, a change in feeling during sex, or pain, tingling, weakness or numbness in both legs, since these can mean pressure on the nerves at the base of the spine, which needs emergency treatment
• Movement partly lost in an arm or a leg, or weakness in a limb that is new, since enlarged bone, most often in the spine, can press on the spinal cord or its nerves
• A joint you cannot put weight on or move, or that has moved out of place, or, after a fall or injury, very bad pain or any tingling or numbness
• After an injury, a crack heard as it happened, or skin around it that has turned blue, grey or cold, since these can be signs of a broken bone
• Chest pain that is crushing, tight or like a pressure, that spreads to an arm, the jaw, the neck, the stomach or the back, that comes with breathlessness, sweating, feeling sick or feeling light-headed, or that came on suddenly and does not go away
• Vomiting blood, or bleeding from the back passage that is heavy or will not stop, most of all with faintness, confusion or pain in the abdomen, or vomit that is black or dark brown, since anti-inflammatory tablets, used by some people with Paget's disease to ease pain, can make the stomach bleed
• Lips, mouth, throat or tongue that suddenly swell, a throat that feels tight, very fast breathing or a struggle to breathe or to swallow, skin, tongue or lips turning blue, grey or pale (on black or brown skin this may be easier to see on the palms of the hands or the soles of the feet), becoming suddenly very confused, drowsy or dizzy, or fainting and not being able to be woken, since this can be a severe allergic reaction, anaphylaxis, which can follow a dose of any medicine
• An eye that suddenly and completely loses its sight

Any of these needs an assessment that is urgent, on the same day, from your GP or NHS 111:

• Pain that strikes an affected bone of the spine, the pelvis or a limb suddenly and severely, or comes on after a minor knock or fall, since a bone weakened by Paget's disease breaks more easily and the pain can mean a break, which needs an X-ray the same day at an urgent treatment centre or A&E, with NHS 111 to tell you which; very bad pain, tingling or numbness after the knock or fall, or a joint that takes no weight, will not move or is out of place, is in the first list, and a limb left at an odd angle after the knock or fall is a 999 or A&E emergency too
• Numbness, tingling or pins and needles in an arm or a leg, new or spreading, that has built up over hours or days with pain in the back or the limb, or pain that has begun to travel down a leg, since enlarged bone can press on a nerve; any loss of movement or weakness with it belongs to the first list
• Back pain that is getting worse quickly, since bone enlarged or weakened by Paget's disease in the spine can press on the nerves or break
• Hearing that is lost suddenly in one or both ears, or that has been getting worse over the last few days or weeks, since it may need treating quickly
• Pins and needles around the lips or in the hands or feet, or cramps or spasms in the muscles, in the days after a zoledronic acid drip, since the medicine can lower the calcium in your blood; any difficulty breathing, a heartbeat that has become irregular, confusion, or muscles that lock in place with them is a 999 or A&E emergency, as the calcium may then have fallen very low
• Black or dark red stools, on anti-inflammatory tablets, since a bleed in the stomach or gut has to be found that day
• A new red, painful eye, or sight that has blurred, dimmed or changed, which needs an eye casualty or urgent eye clinic the same day, as does an eye that light hurts, since zoledronic acid can, uncommonly, inflame the eye

A fever that has not settled within a few days of a zoledronic acid drip, or that is climbing, needs your GP or NHS 111 the same day, since it has gone beyond the drip's usual reaction and its cause has to be found. Short of the signs in the lists above, these are for your GP or your team to see within days: a change in your hearing that has crept on over months, ringing in the ears, or a headache that has come on gradually and will not go away, where Paget's disease affects the skull; trouble with your balance, or numbness or tingling in an arm or a leg, that has come on slowly; and a new lump or swelling at an affected bone, or pain there that has changed in character. Hearing lost to Paget's disease can be permanent, so its cause needs finding, though it is not known whether treatment protects the hearing. Rarely, a bone cancer can start in an affected bone, and it may be possible to cure it if it is found early. An ache in an affected bone that has built up slowly, a bone that is bowing or changing shape, or an aching joint beside an affected bone are for a routine review by your GP or team, since pain can come from the bone itself, from a nearby joint or from a nerve, and each is treated differently. If you cannot tell how urgent something is, asking is never a mistake.

Treatment for Paget's disease usually works well. An assessment settles whether you need it, and follow-up keeps track of the affected bone. Bone pain without an explanation, a high alkaline phosphatase on a blood test, or a bone that looks changed on a scan can all be untangled by a specialist.

Which tests find Paget's disease of bone?

The first clue is often a blood test with a raised alkaline phosphatase, an enzyme that bone releases, or a change spotted on an X-ray taken for some other purpose. Imaging settles it, and a radionuclide bone scan is the best way to map which bones are involved and how active they are. The doctor also weighs up whether any bone is giving trouble now, or may do later, before a plan is made with you.

Will I need treatment for it?

Not necessarily. Plenty of people have no symptoms and no bone at risk, and keeping an eye on things may then be enough. When treatment is given, it calms the overactive turnover of bone and can help relieve symptoms, and pain coming from the Paget's bone itself is the main reason to give it. Whether to treat depends on your pain, on where the disease is and on how likely complications are, and you decide it together with your doctor.

What happens if I am treated?

Bisphosphonates are the usual medicine: they quieten the overactive renewal of bone, and most people have them as a single drip of zoledronic acid, usually in a hospital clinic. Before that, your calcium and vitamin D are measured and corrected where low, because enough vitamin D, with a good calcium intake, makes the calcium less likely to drop after the drip, and supplements are usually taken for several days afterwards. The alkaline phosphatase level is checked later to see how the bone has responded, though treatment is aimed at your symptoms, not at bringing that number back to normal. Painkillers can be taken alongside if needed.

How do people get on after treatment?

Well, for most: the disease's activity answers well to treatment, though it is less certain that treatment prevents its complications. In the months after a bisphosphonate drip the enzyme level in the blood tends to come down as the bone quietens, and bone pain often lessens. A single dose of zoledronic acid can keep working for many years, so a repeat is often not needed for a long time. A blood test a few months after the drip shows how the bone has answered, and later checks pick up when the effect starts to wear off.

Is Paget's disease the same thing as osteoporosis?

No. The two are distinct, although each concerns bone and a person can have both. In osteoporosis bone thins throughout the skeleton, raising the chance of a break, and there is seldom pain until a bone breaks. Paget's disease upsets the renewal of particular bones, which may grow weaker, larger or misshapen and can hurt where they are affected. Both are assessed as part of a broader review of your bones, and both can be managed well.