Foot care in diabetes

INTRODUCTION — Diabetes can lead to a number of different foot complications. Fortunately, most of these complications can be prevented with a little extra foot care. If complications do occur, daily attention will ensure that they are detected before they become serious. It may take time and effort to build good foot care habits, but self-care is essential. In fact, when it comes to foot care, the patient is a vital member of the medical team.

This topic review presents a general overview of diabetic foot complications and guidelines for good foot care. Patients should discuss foot care with their own doctor to determine the best guidelines and treatments.

DIABETES AND FOOT COMPLICATIONS — Longstanding high blood sugar can damage blood vessels, decreasing blood flow to the foot. This poor circulation can weaken the skin, contribute to the formation of ulcers, and impair wound healing. Some bacteria and fungi thrive on high levels of sugar in the bloodstream, and bacterial and fungal infections can break down the skin and complicate ulcers.

In addition, high blood sugar can damage the nerves of the foot, decreasing a patient's ability to notice pain and pressure. Without these sensations, it is easy to develop callused pressure spots and accidentally injure the skin, soft tissue, bones, and joints. Over time, bone and joint damage can dramatically alter the shape of the foot. Nerve damage can also weaken certain foot muscles, further contributing to foot deformities.

CONSEQUENCES OF FOOT COMPLICATIONS — Diabetes can lead to many different types of foot complications, including athlete's foot (a fungal infection), calluses, bunions and other foot deformities, and ulcers that can range from superficial to very deep.

More serious complications include deep skin and bone infections. Gangrene (death and decay of tissue) is a very serious complication that may include infection; widespread gangrene may require foot amputation. Approximately 5 percent of men and women with diabetes eventually require amputation of a toe or foot. This tragic consequence can be prevented in most patients by managing blood sugar levels and daily foot care.

RISK FACTORS — Patients who have had a previous foot ulcer are more likely to have future foot complications. Nerve damage, poor circulation, and chronically high blood sugar levels also increase the likelihood of foot complications.

Footwear — It is important to wear shoes that fit well. Shoes that are too tight can cause pressure ulcers. Going barefoot, even in the home, should be avoided as this increases the risk of injury to the foot.

FOOT EXAMINATION — Patients who have had type 1 diabetes for at least five years should have their feet examined at least once a year. Patients who have type 2 diabetes should have their feet examined once a year after their diagnosis.

During a foot exam, a healthcare provider checks for signs and symptoms of poor circulation, nerve damage, skin changes, and deformities. Patients should mention any problems they have noticed in their feet.

An exam may reveal decreased or absent reflexes or decreased ability to sense pressure, vibration, pin pricks, and changes in temperature.

Special devices, including a monofilament or tuning fork, can help determine the extent of nerve damage. A monofilament is a very thin, flexible thread that is used to determine if a patient can sense pressure in various areas of the foot (show figure 1). A tuning fork is used to determine if a patient can sense vibration in various areas, especially the foot and toe joints.

Possible foot problems

Poor circulation — Some simple clues can point to circulatory problems. Poor pulses, cold feet, thin or blue skin, and lack of hair signal that the feet are not getting enough blood.

Nerve damage — Nerve damage may lead to unusual sensations in the feet and legs, including pain, burning, numbness, tingling, and fatigue. Patients should describe these symptoms if they occur, including the timing, if the feet, ankles, or calves are affected, and what measures relieve the symptoms.

Nerve damage may cause no symptoms as the foot and leg slowly lose sensation and become numb. This can be very dangerous because the person may be unaware that they have improperly fit shoes, a rock or other irritant in a shoe, or other problems that could cause damage.

Skin changes — Excessive skin dryness, scaling, and cracking indicate that the circulation to this protective tissue is compromised. Other skin changes may include healed or new ulcers, calluses, and broken skin between the toes (show picture 2).

Deformities — The structure and appearance of the feet and foot joints can indicate diabetic complications. Nerve damage can lead to joint and other foot deformities. The toes may have a peculiar "claw toe" appearance, and the foot arch and other bones may appear collapsed. This destruction of the bones and joints is called Charcot arthropathy (show picture 3).

PREVENTING FOOT PROBLEMS — Controlling blood sugar levels can reduce the blood vessel and nerve damage that often lead to diabetic foot complications. If a foot wound or ulcer does occur, blood sugar control reduces the risk of requiring amputation. (See "Patient information: Self-blood glucose monitoring").

Foot care is important, although patients should also continue to follow other general guidelines for managing diabetes.

The following simple, everyday actions can reduce the chances of developing foot problems.

Quit smoking — Smoking can worsen heart and vascular problems and reduce circulation to the feet.

Avoid activities that can injure the feet — Some activities increase the risk of foot injury and are not recommended, including walking barefoot, using a heating pad or hot water bottle on the feet, and stepping into the bathtub before testing the temperature. This caution cannot be emphasized enough; foot injury is a preventable cause of foot amputation.

Use care when trimming the nails — Trim the toe nails along the shape of the toe and file the nails to remove any sharp edges (show figure 2). Never cut (or allow a manicurist to cut) the cuticles. Do not open blisters, try to free ingrown toenails, or otherwise break the skin on the feet. See a healthcare provider or podiatrist for even minor procedures.

Wash and check the feet daily — Use lukewarm water and mild soap to clean the feet. Gently pat your feet dry and apply a moisturizing cream or lotion.

Check the entire surface of both feet for skin breaks, blisters, swelling, or redness, including between and underneath the toes where damage can be hidden. Use a mirror if it is difficult to see all parts of the feet, or ask a family member or caregiver to help.

Choose socks and shoes carefully — Select cotton socks that fit loosely, and change the socks every day. Select shoes that are snug but not tight, and break new shoes in slowly to prevent any blisters (show figure 3). Ask about customized shoes if the feet are misshapen or have already developed foot ulcers; these specialized shoes can reduce the chances of developing foot ulcers in the future. Shoe inserts may also help cushion the step and decrease pressure on the soles of the feet.

Make good foot care a habit — Good foot care in not optional. Try to follow these guidelines daily.

Ask for foot exams — Screening for foot complications should be a routine part of most medical visits, but is sometimes overlooked. Don't hesitate to ask the healthcare provider for a foot check at least once a year, and more frequently if there are foot changes.

TREATMENT OF FOOT PROBLEMS — The treatment of foot problems depends upon the presence and severity of foot ulcers.

Superficial ulcers involving only the top layers of skin usually includes cleaning the ulcer and removing dead skin and tissue (debridement) by a healthcare provider (show picture 1). There are a number of debridement techniques available; hydrogels may be more effective than gauze or other methods in healing foot ulcers.

If the foot is infected, antibiotics are generally prescribed. The patient (or someone in his or her household) should clean the ulcer and apply a clean dressing twice daily. The patient should keep weight off the foot ulcer as much as possible, meaning that they should not walk with the affected foot. Patients should keep the foot elevated. The ulcer should be checked by a healthcare provider at least once a week to make sure that treatment is healing the ulcer.

Ulcers that have extended into the deeper layers of the foot, involving muscle and bone, usually require hospitalization (show picture 4). More extensive laboratory testing and x-rays may be done, and intravenous antibiotics are often necessary. Surgery may be necessary to remove infected bone or to put a cast on the foot to take pressure off the ulcer.

If part of the toes or foot become severely damaged, and areas of dead tissue that have no chance of healing (gangrene) develop, partial or complete amputation may be required. This is reserved for patients who do not heal despite aggressive treatment, or whose health is threatened by the gangrene.

Some patients with severe foot ulcers and peripheral vascular disease (poor circulation) may require a procedure to restore blood flow to the foot, and potentially avoid amputation. (See "Patient information: Claudication").

NEW TREATMENTS — Several experimental approaches are being evaluated for the treatment of diabetic foot complications. New options that may help heal ulcers include synthetic wound dressings, skin grown in a laboratory, substances that stimulate healing and support the growth of infection-fighting cells, electrical stimulation, and exposure to elevated oxygen levels.

For patients with diabetes, foot complications are an ever-present risk. However, patients and their healthcare provider can design a plan for keeping the feet as healthy as possible. Patients should learn as much as possible about diabetic foot care and take an active role in medical decisions and care. While routine medical exams are certainly important, everyday foot care plays the largest role in stopping foot complications before they start.

WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.

This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.

A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine

(www.nlm.nih.gov/medlineplus/healthtopics.html)
National Institute of Diabetes and Digestive and Kidney Diseases

(www.niddk.nih.gov)
American Diabetes Association (ADA)

(800)-DIABETES (800-342-2383)
(www.diabetes.org)
The Endocrine Society

(www.endo-society.org)


[1-4]


Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Ramsey, SD, Newton, K, Blough, D, et al. Incidence, outcomes, and cost of foot ulcers in patients with diabetes. Diabetes Care 1999; 22:382.
2. Mayfield, JA, Reiber, GE, Sanders, LJ, et al. Preventive foot care in diabetes. Diabetes Care 2004; 27 Suppl 1:S63.
3. Pham, H, Armstrong, DG, Harvey, C, et al. Screening techniques to identify people at high risk for diabetic foot ulceration: a prospective multicenter trial. Diabetes Care 2000; 23:606.
4. Litzelman, DK, Marriott, DJ, Vinicor, F. The role of footwear in the prevention of foot lesions in patients with NIDDM. Diabetes Care 1997; 20:156.