Diabetes mellitus (DM) represents several diseases in which high blood glucose levels over time can damage the nerves, kidneys, eyes, and blood vessels. Diabetes can also decrease the body's ability to fight infection. When diabetes is not well controlled, damage to the organs and impairment of the immune system is likely. Foot problems commonly develop in people with diabetes and can quickly become serious.
- With damage to the nervous system, a person with diabetes may not be able to feel his or her feet properly. Normal sweat secretion and oil production that lubricates the skin of the foot is impaired. These factors together can lead to abnormal pressure on the skin, bones, and joints of the foot during walking and can lead to breakdown of the skin of the foot. Sores may develop.
- Damage to blood vessels and impairment of the immune system from diabetes make it difficult to heal these wounds. Bacterial infection of the skin, connective tissues, muscles, and bones can then occur. These infections can develop into gangrene. Because of the poor blood flow, antibiotics cannot get to the site of the infection easily. Often, the only treatment for this is amputation of the foot or leg. If the infection spreads to the bloodstream, this process can be life-threatening.
- People with diabetes must be fully aware of how to prevent foot problems before they occur, to recognize problems early, and to seek the right treatment when problems do occur. Although treatment for diabetic foot problems has improved, prevention - including good control of blood sugar level - remains the best way to prevent diabetic complications.
- People with diabetes should learn how to examine their own feet and how to recognize the early signs and symptoms of diabetic foot problems.
- They should also learn what is reasonable to manage routine at home foot care, how to recognize when to call the doctor, and how to recognize when a problem has become serious enough to seek emergency treatment.
Diabetic Foot Care Causes
Several risk factors increase a person with diabetes chances of developing foot problems and diabetic infections in the legs and feet.
- Footwear: Poorly fitting shoes are a common cause of diabetic foot problems.
- If the patient has red spots, sore spots, blisters, corns, calluses, or consistent pain associated with wearing shoes, new properly fitting footwear must be obtained as soon as possible.
- If the patient has common foot abnormalities such as flat feet, bunions, or hammertoes, prescription shoes or shoe inserts may be necessary.
- Nerve damage: People with long-standing or poorly controlled diabetes are at risk for having damage to the nerves in their feet. The medical term for this is peripheral neuropathy.
- Because of the nerve damage, the patient may be unable to feel their feet normally. Also, they may be unable to sense the position of their feet and toes while walking and balancing. With normal nerves, a person can usually sense if their shoes are rubbing on the feet or if one part of the foot is becoming strained while walking.
- A person with diabetes may not properly sense minor injuries (such as cuts, scrapes, blisters), signs of abnormal wear and tear (that turn into calluses and corns), and foot strain. Normally, people can feel if there is a stone in their shoe, then remove it immediately. A person who has diabetes may not be able to perceive a stone. Its constant rubbing can easily create a sore.
- Poor circulation: Especially when poorly controlled, diabetes can lead to accelerated hardening of the arteries or atherosclerosis. When blood flow to injured tissues is poor, healing does not occur properly.
- Trauma to the foot: Any trauma to the foot can increase the risk for a more serious problem to develop.
- Athlete's foot, a fungal infection of the skin or toenails, can lead to more serious bacterial infections and should be treated promptly.
- Ingrown toenails should be handled right away by a foot specialist. Toenail fungus should also be treated.
- Smoking: Smoking any form of tobacco causes damage to the small blood vessels in the feet and legs. This damage can disrupt the healing process and is a major risk factor for infections and amputations. The importance of smoking cessation cannot be overemphasized
Diabetic Foot Care Symptoms
- Persistent pain can be a symptom of sprain, strain, bruise, overuse, improperly fitting shoes, or underlying infection.
- Redness can be a sign of infection, especially when surrounding a wound, or of abnormal rubbing of shoes or socks.
- Swelling of the feet or legs can be a sign of underlying inflammation or infection, improperly fitting shoes, or poor venous circulation. Other signs of poor circulation include the following:
- Pain in the legs or buttocks that increases with walking but improves with rest (claudication)
- Hair no longer growing on the lower legs and feet
- Hard shiny skin on the legs
- Localized warmth can be a sign of infection or inflammation, perhaps from wounds that won't heal or that heal slowly.
- Any break in the skin is serious and can result from abnormal wear and tear, injury, or infection. Calluses and corns may be a sign of chronic trauma to the foot. Toenail fungus, athlete's foot, and ingrown toenails may lead to more serious bacterial infections.
- Drainage of pus from a wound is usually a sign of infection. Persistent bloody drainage is also a sign of a potentially serious foot problem.
- A limp or difficulty walking can be sign of joint problems, serious infection, or improperly fitting shoes.
- Fever or chills in association with a wound on the foot can be a sign of a limb-threatening or life-threatening infection.
- Red streaking away from a wound or redness spreading out from a wound is a sign of a progressively worsening infection.
- New or lasting numbness in the feet or legs can be a sign of nerve damage from diabetes, which increases a persons risk for leg and foot problems.
When to Seek Medical Care
Write down the patient's symptoms and be prepared to talk about them on the phone with a doctor. Following is a list of common reasons to call a doctor if a person with diabetes has a diabetic foot or leg problem. For most of these problems, a doctor visit within about 72 hours is appropriate.
- Any significant trauma to the feet or legs, no matter how minor, needs medical attention. Even minor injuries can result in serious infections.
- Persistent mild-to-moderate pain in the feet or legs is a signal that something is wrong. Constant pain is never normal.
- Any new blister, wound, or ulcer less than 1 inch across can become a more serious problem.
The patient will need to develop a plan with a doctor on how to treat these wounds.
- Any new areas of warmth, redness, or swelling on the feet or legs are frequently early signs of infection or inflammation. Addressing them early may prevent more serious problems.
- Pain, redness, or swelling around a toenail could mean the patient has an ingrown toenail - a leading cause of diabetic foot infections and amputations. Prompt and early treatment is essential.
- New or constant numbness in the feet or legs can be a sign of diabetic nerve damage (neuropathy) or of impaired circulation in the legs. Both conditions put the patient at risk for serious problems such as infections and amputations.
- Difficulty walking can result from diabetic arthritis (Charcot's joints), often a sign of abnormal strain or pressure on the foot or of poorly fitting shoes. Early intervention is key to preventing more serious problems including falls as well as lower extremity skin breakdown and infections.
- Constant itching in the feet can be a sign of fungal infection or dry skin, both of which can lead to infection.
- Calluses or corns developing on the feet should be professionally removed. Home removal is not recommended.
- Fever, defined as a temperature over 98.6°F (37°C), in association with any other symptoms or even fever alone should prompt a call to a doctor's office. The degree of fever does not always correlate with the seriousness of infection. The patient could have no fever or a very low fever and still have a serious infection. People with diabetes need to be especially cautious of fever.
If time and the patient's condition permits, write down the patient's symptoms, a list of medications, allergies to medicines, and the doctor's name and phone number prior to coming to the hospital's emergency department. This information will greatly assist the emergency physician in the evaluation and treatment of the patient's problem.
Following are some common reasons to seek immediate medical attention for diabetic foot and leg problems.
- Severe pain in the feet or legs is often a sign of acute loss of circulation to the leg, serious infection, or may be due to severe nerve damage (neuropathy).
- Any cut to the feet or legs that bleeds significantly and goes all the way through the skin needs proper cleaning and repair to aid healing.
- Any significant puncture wounds to the feet (for example, stepping on a nail or being bitten by a dog or cat) carry a high risk of becoming infected.
- Wounds or ulcers that are more than about 1 inch across on the feet or legs are frequently associated with limb-threatening infections.
- Redness or red streaks spreading away from a wound or ulcer on the feet or legs are a sign of infection spreading through the tissues.
- Fever higher than 101.5°F (38.6°C) in association with redness, swelling, warmth, or any wound or ulcer on the legs may be a sign of a limb-threatening or life-threatening infection. If you are a person with diabetes and you simply have a fever more than 101.5°F (38.6°C), and no other symptoms, seek immediate care to determine the source of the fever and to initiate a plan of care. Because the degree of fever does not always correlate with the seriousness of the illness, people with diabetes should take even low-grade fevers [less than101.5°F (38.6°C)] very seriously and seek medical attention. The patient's doctor may or may not prescribe antibiotics, since fevers are often due to viral infections, which typically do not require antibiotics.
- Alteration in mental status (confusion) may be a sign of life-threatening infection that could lead to loss of a leg or foot, when associated with a leg wound or foot ulcer. Confusion may also be a sign of either very high or very low blood sugars, which are more common when infection is present
Exams and Tests
Medical evaluation should include a thorough history and physical examination and may also include laboratory tests, x-ray studies of circulation in the legs, and consultation with specialists.
- History and physical examination: First, the doctor will ask the patient questions about their symptoms and will examine them. This examination should include the patient's vital signs (temperature, pulse, blood pressure, and respiratory rate), examination of the sensation in the feet and legs, an examination of the circulation in the feet and legs, a thorough examination of any problem areas. For a lower extremity wound or ulcer, this may involve probing the wound with a blunt probe to determine its depth. Minor surgical debridement of the wound (cleaning or cutting away of tissue) may be necessary to determine the seriousness of the wound.
- Laboratory tests: The doctor may decide to order a complete blood cell count, or CBC, which will assist in determining the presence and severity of infection. A very high or very low white blood cell count suggests serious infection. The doctor may also check the patient's blood sugar either by fingerstick or by a laboratory test. Depending on the severity of the problem, the doctor may also order kidney function tests, blood chemistry studies (electrolytes), liver enzyme tests, and heart enzyme tests to assess whether other body systems are working properly in the face of serious infection.
- X-rays: The doctor may order x-rays studies of the feet or legs to assess for signs of damage to the bones or arthritis, damage from infection, foreign bodies in the soft tissues. Gas in the soft tissues, indicates gangrene - a very serious, potentially life-threatening or limb-threatening infection.
- Ultrasound: The doctor may order Doppler ultrasound to see the blood flow through the arteries and veins in the lower extremities. The test is not painful and involves the technician moving a non-invasive probe over the blood vessels of the lower extremities.
- Consultation: The doctor may ask a vascular surgeon, orthopedic surgeon, or both to examine the patient. These specialists are skilled in dealing with diabetic lower extremity infections, bone problems, or circulatory problems.
- Angiogram: If the vascular surgeon determines that the patient has poor circulation in the lower extremities, an angiogram may be performed in preparation for surgery to improve circulation.
With an angiogram, a catheter is inserted through the artery in the groin and dye is injected while x-rays are taken. This allows the surgeon to see where the blockages are and plan an operation to bypass the blockages. This procedure is usually performed with local anesthesia and a light sedative given through a tube inserted in the patient's vein (an intravenous or IV line).
Diabetic Foot Care Treatment
Self-Care at Home
A person with diabetes should do the following:
- Foot examination: Examine your feet daily and also after any trauma, no matter how minor, to your feet. Report any abnormalities to your physician. Use a water-based moisturizer every day (but not between your toes) to prevent dry skin and cracking. Wear cotton or wool socks. Avoid elastic socks and hosiery because they may impair circulation.
- Eliminate obstacles: Move or remove any items you are likely to trip over or bump your feet on. Keep clutter on the floor picked up. Light the pathways used at night - indoors and outdoors.
- Toenail trimming: Always cut your nails with a safety clipper, never a scissors. Cut them straight across and leave plenty of room out from the nailbed or quick. If you have difficulty with your vision or using your hands, let your doctor do it for you or train a family member how to do it safely.
- Footwear: Wear sturdy, comfortable shoes whenever feasible to protect your feet. To be sure your shoes fit properly, see a podiatrist (foot doctor) for fitting recommendations or shop at shoe stores specializing in fitting people with diabetes. Your endocrinologist (diabetes specialist) can provide you with a referral to a podiatrist or orthopedist who may also be an excellent resource for finding local shoe stores. If you have flat feet, bunions, or hammertoes, you may need prescription shoes or shoe inserts.
- Exercise: Regular exercise will improve bone and joint health in your feet and legs, improve circulation to your legs, and will also help to stabilize your blood sugar levels. Consult your physician prior to beginning any exercise program.
- Smoking: If you smoke any form of tobacco, quitting can be one of the best things you can do to prevent problems with your feet. Smoking accelerates damage to blood vessels, especially small blood vessels leading to poor circulation, which is a major risk factor for foot infections and ultimately amputations.
- Diabetes control: Following a reasonable diet, taking your medications, checking your blood sugar regularly, exercising regularly, and maintaining good communication with your physician are essential in keeping your diabetes under control. Consistent long-term blood sugar control to near normal levels can greatly lower the risk of damage to your nerves, kidneys, eyes, and blood vessels.
- Antibiotics: If the doctor determines that a wound or ulcer on the patient's feet or legs is infected, or if the wound has high a risk of becoming infected, such as a cat bite, antibiotics will be prescribed to treat the infection or the potential infection. It is very important that the patient take the entire course of antibiotics as prescribed. Generally, the patient should see some improvement in the wound in two to three days and may see improvement the first day. For limb-threatening or life-threatening infections, the patient will be admitted to the hospital and given IV antibiotics. Less serious infections may be treated with pills as an outpatient. The doctor may give a single dose of antibiotics as a shot or IV dose prior to starting pills in the clinic or emergency department.
- Referral to wound care center: Many of the larger community hospitals now have wound care centers specializing in the treatment of diabetic lower extremity wounds and ulcers along with other difficult-to-treat wounds. In these multidisciplinary centers, professionals of many specialties including doctors, nurses, and therapists work with the patient and their doctor in developing a treatment plan for the wound or leg ulcer. Treatment plans may include surgical debridement of the wound, improvement of circulation through surgery or therapy, special dressings, and antibiotics. The plan may include a combination of treatments.
- Referral to podiatrist or orthopedic surgeon: If the patient has bone-related problems, toenail problems, corns and calluses, hammertoes, bunions, flat feet, heel spurs, arthritis, or have difficulty with finding shoes that fit, a physician may refer you to one of these specialists. They create shoe inserts, prescribe shoes, remove calluses and have expertise in surgical solutions for bone problems. They can also be an excellent resource for how to care for the patient's feet routinely.
- Home health care: The patient's doctor may prescribe a home health nurse or aide to help with wound care and dressings, monitor blood sugar, and help the patient take antibiotics and other medications properly during the healing period.
- Read any instructions from the doctor while the patient are still in the emergency department or doctor's office. Ask questions about any instructions you don't understand. Follow all of your doctor's or nurse's instructions. Let a doctor know if the patient's condition is not improving within a reasonable time.
- Be sure to finish the entire course of antibiotics if prescribed by the doctor. Not finishing the entire course can lead to bacteria becoming resistant to antibiotics.
- Less pain, swelling, redness, warmth, or drainage are generally all signs of improvement in an infected wound. Shrinkage of the wound or ulcer is a good sign. Absence of fever is also generally a good sign. Generally, some improvement should occur within the first two to three days. Let a doctor know if the patient is not improving as expected.
- Be especially vigilant about the patient's diabetes care while they are healing a foot or leg infection. Good glycemic control is good not only for healing an ulcer the patient already has, but also for preventing future ulcers. Check blood sugar regularly and let a doctor know the pattern of low and high levels
Prevention of diabetic foot problems involves a combination of factors.
- Good diabetes control
- Regular leg and foot self-examinations
- Knowledge on how to recognize problems
- Choosing proper footwear
- Regular exercise, if able
- Avoiding injury by keeping footpaths clear
- Having a doctor examine the patient's feet at least once a year using a monofilament, a device made of nylon string that tests sensation
- Age: The older the patient, the more likely they are to have serious problems with the feet and legs. In addition to diabetes, circulatory problems and nerve damage are more common in the elderly person with diabetes. The elderly may also be more prone to sustaining minor trauma to the feet from difficulties with walking and stumbling over obstacles they cannot see.
- Duration of diabetes: The longer the patient has had diabetes, the more likely they have developed one or more major risk factors for diabetic lower extremity problems.
- Seriousness of infection: Infections that involve gangrene almost universally go on to amputation and also carry a high risk of death. Ulcers larger than about 1 inch across have a much higher risk of progressing on to limb amputation, even with proper treatment. Infections involving deep tissues and bone carry a much higher risk of amputation.
- Quality of circulation: If blood flow is poor in the patient's legs as a result of damage to the blood vessels from smoking or diabetes or both, it is much more difficult to heal wounds. The likelihood of more serious infection and amputation is greater.
- Compliance with the treatment plan: How well the patient follows and participates in the treatment plan developed with doctors and nurses is crucial to the best recovery possible. Ask questions if any aspects of the care or treatment plan are unclear. Let the doctor know if something in the plan doesn't seem to be working.
- Wound care centers: A wound care center is an excellent resource if available. It brings together many specialists and approaches to aid in the treatment of the diabetic foot problem. These centers will often be able to offer the most up-to-date therapies and even may have experimental protocols available for people who have not responded to traditional therapy.
- Individual physician and nurse skills: Ask about your doctor or nurse's expertise in dealing with diabetic lower extremity problems. Knowledge about and experience with these problems may lead to earlier diagnosis and more appropriate therapy.