by David G. Armstrong, DPM, MD, PhD
People with diabetes are often told to pay close attention to their feet — and for good reason. While having diabetes doesn’t make it more likely that you’ll injure your feet in the first place, having certain common diabetes complications raises the risk of minor foot problems becoming major foot problems if not treated promptly.
One of those complications is peripheral neuropathy, or damage to the nerves in the feet and lower legs. Peripheral neuropathy can cause a loss of sensation in the feet, meaning that heat, cold, and/or pain may not be felt. As a result, a person becomes more vulnerable to getting burned if he steps into hot water or walks barefoot on hot pavement or sand, and he’s also more likely to let small blisters, cuts, and scrapes on his feet go untreated since he doesn’t feel them.
The other common diabetes-related complication that raises the risk of foot problems is reduced blood circulation to the feet. Blood carries oxygen and other nutrients and substances that are necessary for wound healing. When blood circulation is reduced, wounds heal more slowly and have more time to become infected.
The good news is that many if not most major foot problems are avoidable. How to do it? Maintain the best blood glucose and blood pressure control possible. Wear well-fitting shoes or slippers at all times (except for sleeping or bathing), and check inside them for foreign objects before putting them on. Check the tops and bottoms of your feet and between your toes every day, especially if you know or suspect you have either neuropathy or reduced blood circulation. Look or feel for any signs of rubbing, injury, or infection, such as redness, broken skin, or areas of unusual warmth.
If you develop a foot problem, attend to it immediately. Apply first-aid measures to small cuts or blisters, then check daily to see whether the wound is healing. Stop wearing any shoes or socks that rub on or bother your feet in any way. And call your diabetes care provider promptly if small wounds do not heal quickly or if you sustain a serious foot injury.
Resolving common problems
Having any kind of foot problem can interfere with your daily life. Here’s how to address some common complaints and keep your feet in good health.
I’d like to walk more for exercise, but my feet hurt when I walk.
Your feet may be hurting for a number of reasons, most of which can be prevented or treated by changing your activity, your shoes, or the insoles in your shoes.
In general, the more active you are, the better you will feel, and walking is a good choice of activity for many people. However, if you have diabetes-related foot problems, check with your doctor about how much walking is safe for you. It may be advisable to alternate between walking and activities that put less stress on your feet, such as bicycling, swimming, or water aerobics. (Be sure to wear water shoes when exercising in water.)
If walking is safe for you, choose walking shoes that are flexible enough to walk in easily but that also provide support and cushioning. Wear socks that provide some cushioning and that wick away sweat. Remember that even the best shoes won’t last forever, and the more you weigh, the faster your shoes will wear out. Generally, shoes will last for no more than 500 miles, which usually equals three to six months of regular walking. Plan on buying a new pair of walking shoes before the old ones wear out so that you can “break in” the new ones a little at a time. (Although shoes should fit well and be comfortable at the time of purchase, it’s recommended that you wear them for only short periods at first and gradually lengthen the time you walk in them.)
If your feet still hurt with well-fitting shoes, or your feet have changed shape so much that no pair of shoes fits well, a podiatrist or other foot expert may be able to recommend insoles or other shoe inserts to allow you to walk comfortably. However, you will still need to replace your shoes at 500-mile intervals (or earlier), and you will most likely need to replace your inserts as well.
I put moisturizing lotion on my feet every day, but the skin on them is still dry and itchy.
Try switching to a thicker lotion or cream, and apply the product more than once a day. For very dry skin, moisturizer should be applied two to four times a day. However, be careful not to put too much between your toes. Too much wetness in this area increases the risk of skin breakdown and infection.
If increased moisturizing doesn’t improve dryness, flaking, or itching, see your primary-care doctor or foot doctor. Very itchy skin is sometimes a sign of a fungal infection such as athlete’s foot.
I have thick calluses on the bottoms of my feet. How can I get rid of them?
Calluses are your body’s way of telling you that you are applying too much pressure to a given area. If you do not have neuropathy, you can use over-the-counter tools to “grate” or file down the callus. The Ped Egg, for example, works well. After reducing the callus, moisturize the skin with a high-quality cream.
If you have neuropathy, calluses are far more serious, because you run the risk of developing an undetected wound underneath the callus. Do not try to treat calluses yourself; instead, have your foot doctor check them regularly. You can prevent calluses in the future by modifying the shoes or insoles you wear to reduce the stress on the area getting callused. Over-the-counter insoles can sometimes work well. For more significant problems, your foot specialist may prescribe insoles or shoe modifications.
Rarely, surgery is required to correct the underlying deformity leading to calluses. This may be considered as an option if a callus puts a person at high risk for developing a foot ulcer.
I’d really like to get a pedicure so my feet look good in sandals, but I’ve heard that people with diabetes shouldn’t get pedicures. Why is this?
People with diabetes are often advised not to get pedicures because of the possibility that salon workers will create small (or large) breaks in the skin while performing the pedicure. Any break in the skin is an access point for dirt and germs, possibly leading to an infection. The other concern about pedicures is that the toenail clippers and other implements used will not be clean, also raising the risk of acquiring an infection at the nail salon.
This doesn’t mean that pedicures are completely off-limits for people with diabetes who have good foot health. Provided the salon is reputable and has a good record of safety, you can get pedicures. However, if you have neuropathy or significant vascular disease, it’s best to forego pedicures: The potential consequences of getting an infection are too high.
I have a hard time cutting my own toenails. Is this something my doctor or a nurse could do for me?
Yes. It is best if a trained medical professional does this, particularly if you have neuropathy or vascular disease. Neuropathy can cause you not to notice small cuts that may occur if toenails are cut improperly or too short, and vascular disease in the legs and feet make you more vulnerable to infection of wounds on the feet.
Your health insurance may cover this type of foot care, but only if your doctor or podiatrist provides evidence that it is medically necessary.
My doctor says I need to treat the fungal infection in my toenails, but I don’t want to take another drug. How important is it really to treat this?
Generally, nail fungus is a cosmetic problem. However, when you have diabetes, fungal infections of the toenails can put you at greater risk for other types of infections and skin problems, particularly as you age. These include bacterial and secondary fungal infections of the skin. For this reason, if your doctor recommends it, you may benefit from a local or systemic treatment for nail fungus.
I have seen advertisements for laser treatment of fungal nails. Is that a good idea?
While it may stand to reason that laser therapy might be effective at killing fungus, the products and treatments currently being advertised really have no data behind them to back them up. If you have otherwise healthy feet and money to spare, you may want to give it a try. However, if you have neuropathy in your feet, vascular disease, or other skin conditions on your feet, I would suggest speaking to your doctor about how best to treat a fungal nail infection.
My feet have changed shape over the years, and it’s hard to find shoes that fit.
It is normal for your feet to flatten very slightly and to change shape, becoming longer and wider, as you age. It’s possible for your shoe size to increase by one or even two sizes over time. That being the case, it is very important to have your feet measured each year to assess your shoe size. A study conducted some years ago by our team in Arizona suggests that three-quarters of people with diabetes wear shoes that are at least one size too big or too small. (Shoes that are too big may allow the feet to slide around, possibly leading to blisters.)
I recommend, at the minimum, an annual visit to your foot specialist for an evaluation. If you have or develop risk factors for diabetes-related foot problems, your specialist may recommend prescription shoes or specific types of over-the-counter shoes. It may also be worth seeking out the services of a certified pedorthist if you have hard-to-fit feet. These footwear specialists may work in medical offices that provide foot care or are sometimes on staff at retail shoe stores that specialize in comfortable shoes. The Pedorthic Footwear Association Web site (www.pedorthics.org) has a search function to find credentialed pedorthists by location.
Shop for shoes later in the day, because feet can swell — sometimes imperceptibly — throughout the day. A shoe that fits well in the morning may be too tight by late afternoon. Buy shoes that provide arch support where you need it and enough room in the toe box for your toes to wiggle a little. Your heel should not lift more than half an inch when you walk.
It’s important that socks fit, too. Look for seamless socks or socks with seams that do not run across the bottoms of the feet or along any bony parts where they can cause pressure. White or light-colored socks are recommended, because any bleeding from a wound on the foot will be noticed quickly.
My feet smell terrible when I take off my shoes. What can I do about this?
This is a very common problem that is generally caused by the growth of bacteria on your feet. Alternating between pairs of shoes so that each pair gets a chance to dry out completely, and changing your socks more than once daily may help. Sprinkling the insides of your shoes with ordinary talcum powder may also reduce odor. If these steps are ineffective, speak to your doctor about alternative approaches. Do not try any home remedies without speaking first to your doctor.
Other common concerns
Unfortunately, many people with diabetes eventually develop neuropathy in their feet, so it’s important to have your doctor examine your feet at least once a year and to know how to protect your feet if you develop it.
My feet are sometimes numb when I wake up in the morning. Does this mean I have diabetic neuropathy?
You may, and your diabetes care doctor or foot specialist can evaluate this with a few simple tests in his office. It’s important to know whether you have neuropathy, or “loss of protective sensation,” in your feet, because that allows you to be proactive about protecting your feet.
Why do doctors say I should check my feet every day?
A daily foot check is one of the best ways to prevent foot complications, including ulcers. It is especially important if you have neuropathy, since you may not feel small injuries to your feet, but it’s a good habit for anyone to check their feet daily for signs of shoe rubbing, blisters, cuts, and calluses. These signs can alert you to the need to change your shoes or socks or to apply first aid. Once you’ve attended to a minor foot problem, check it daily to see if it’s healing normally.
What if you can’t see the bottoms of your feet? Ask a member of your household to look for you, or use a mirror to look yourself. A product called the Insight Foot Care Scale is both a scale (to weigh yourself) and an illuminated, magnified mirror. It automatically lights up after you weigh yourself as a reminder to check your feet. (You should sit down before examining each foot in the mirrored surface.) You can also press a button to turn on the lighted mirror if you don’t wish to weigh yourself first. (Learn more about Insight products at http://www.focusonyourfeet.com.)
If you have vision loss and cannot see your feet even in a magnified mirror, feel them carefully with your hands. Rub the back of your hand (which is especially sensitive to temperature) along each foot to help you detect cool spots, which may indicate impaired circulation, or unusually warm areas, which could be signs of inflammation and infection.
I’ve had an ulcer on my foot, and I’d really like to prevent another one. How can I do this?
In addition to performing a daily visual or manual foot check, using a skin thermometer to detect areas of inflammation on the feet can be very helpful. The TempTouch is an example of such a thermometer. (Read more about using the TempTouch at http://www.temptouch.com.)
Inflammation is a sign that a wound may be developing. By measuring the skin temperature at specific points on both feet and comparing the corresponding points on each foot, inflammation can be caught early. A difference of more than 3–4 degrees indicates that a hot spot may need to be looked at by a doctor.
Reason for hope
Attending to minor foot problems early is the best way to prevent major ones. But if you develop a more serious problem, don’t give up hope. Each year, new products and methods are developed for treating diabetes-related foot problems. Take advantage of these medical advances by bringing your foot problems to your primary-care or foot doctor’s attention promptly. Then take an active role in following through with your foot professional’s recommendations. When you work together with your medical team, there’s good reason to hope that your feet will last a lifetime.
Dr. Armstrong is Professor of Surgery and Director of the Southern Arizona Limb Salvage Alliance (SALSA) at the University of Arizona College of Medicine in Tucson, Arizona. You can follow Dr. Armstrong’s blog posts and other writings via Twitter at www.twitter.com/dgarmstrong or go directly to the SALSA Web site, www.diabeticfootonline.com.
Source: The outstanding patient website “Diabetes Self-Management”