Neuropathy is the medical term for nerve damage. Neuropathy is a common complication of type 1 and type 2 diabetes; up to 26 percent of people with type 2 diabetes have evidence of nerve damage at the time that diabetes is diagnosed . A generalized type of neuropathy, known as polyneuropathy, is the most common type of diabetic neuropathy. Other types of neuropathy can also affect people with diabetes, but will not be discussed here.
Signs and symptoms of diabetic neuropathy include loss of sensation and/or burning pain in the feet. Early detection of diabetes and tight control of blood sugar levels may reduce the risk of developing diabetic neuropathy.
Treatments for diabetic neuropathy are available, and include several elements: control of blood glucose levels, prevention of injury, and control of painful symptoms.
In people with type 1 or type 2 diabetes, the biggest risk factor for developing diabetic neuropathy is having high blood sugar levels over time.
Other factors can further increase the risk of developing diabetic neuropathy, including:
- Coronary artery disease
- Increased triglyceride levels
- Being overweight (a body mass index >24)
- High blood pressure
The most common symptoms of diabetic neuropathy include pain, burning, tingling, or numbness in the toes or feet, and extreme sensitivity to light touch. The pain may be worst at rest and improve with activity, such as walking. Some people initially have intensely painful feet while others have few or no symptoms.
Diabetic neuropathy usually affects both sides of the body. Symptoms are usually noticed first in the toes. If the disease progresses, symptoms may gradually move up the legs; if the mid-calves are affected, symptoms may develop in the hands. Over time, the ability to sense pain may be lost, which greatly increases the risk of injury.
Note: Symptoms vary depending on the nerves affected, and may include symptoms other than those listed. Symptoms usually develop gradually over years.
Potential complications — As you lose the ability to sense pain or hot and cold, your risk of injuring your feet increases. Injuries that would normally cause pain (eg, stepping on a splinter, wearing shoes that create a blister, developing an ingrown toenail) do not necessarily cause pain if you have neuropathy. Unless you inspect your feet on a daily basis, a small injury has the potential to develop into a large ulcer. One of the most serious complications of foot ulcers is the need for amputation of a toe, or in extreme cases, the foot itself.
DIABETIC NEUROPATHY TESTS
Diabetic neuropathy is diagnosed based upon a medical history and physical examination of the feet. During an examination, there may be signs of nerve injury, including:
- Loss of the ability to sense vibration and movement in the toes or feet (eg, when the toe is moved up or down)
- Loss of the ability to sense pain, light touch and temperature in the toes or feet
- Loss or reduction of the Achilles tendon reflex
More extensive testing, including nerve conduction studies, nerve biopsy, or imaging tests (eg, x-ray or CT scan), is not usually needed to diagnose diabetic neuropathy.
DIABETIC NEUROPATHY TREATMENT
There are three main components of diabetic neuropathy treatment:
- Tight control of blood sugar levels
- Care for the feet to prevent complications
- Control of pain caused by neuropathy
Although there is no cure for diabetic neuropathy, use of these treatments can improve painful symptoms and prevent complications.
Control blood sugar levels — One of the most important treatments for diabetic neuropathy is to control blood sugar levels. Symptoms of pain and burning may improve when blood glucose sugar improves.If blood sugar levels are not adequately controlled with the current treatment regimen, a different regimen may be recommended.
- For people with type 1 diabetes, this may mean taking more frequent insulin injections or using an insulin pump.
- For people with type 2 diabetes, this may mean taking an additional oral medication or starting insulin injections.
Care for the feet — People with neuropathy do not always feel pain when there is a wound or injury on the foot. As a result, daily foot care is necessary to monitor for changes in the skin (such as cracks or wounds), which can increase the risk of infection. The Diabetes Association's recommends that people with diabetes have a comprehensive foot examination once per year, and a visual examination of the feet at each visit (usually every three to four months).
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 with the hand.
Use care when trimming the nails — Trim the toe nails along the shape of the toe (rounded, not straight across) and file the nails to remove any sharp edges. Never cut (or allow a manicurist to cut) the cuticles. Do not pop blisters, try to free ingrown toe nails, or otherwise break the skin on the feet. See a doctor or podiatrist for even minor procedures.
Wash and check the feet daily — Use lukewarm water and mild soap to clean the feet. Gently pat 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 may be hidden. Use a mirror or ask a family member or caregiver to help if it is difficult to see the entire foot .
Choose socks and shoes carefully — Select cotton socks that fit loosely, and change the socks every day. Wear shoes that are fit correctly and are not tight, and break new shoes in slowly to prevent blisters . Ask about customized shoes if your feet are misshapen or have ulcers; 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.
Ask for foot exams — Screening for foot complications should be a routine part of most medical visits, but is sometimes overlooked. At each visit, the shoes and socks should be removed and the clinician should visually examine the feet. Do not hesitate to ask the diabetologist for a complete foot check at least once a year, and more frequently if there are problems.
Control pain — Neuropathic pain can be difficult to control and can seriously affect your quality of life. Neuropathic pain is often worse at night, seriously disrupting sleep.Fortunately, only a small percentage of people with diabetic neuropathy experience pain. Pain resolves without treatment in some people over a period of weeks to months, especially if the episode of pain developed after a sudden change in health (eg, an episode of diabetic ketoacidosis, a significant weight loss, or a significant change in blood glucose control).
There are several medications that are useful for the treatment of diabetic neuropathy and have been approved by the FDA, including duloxetine and pregabalin. Other medications are also useful, including tricyclic medications (eg, amitriptyline), gabapentin, tramadol, and alpha-lipoic acid.
Neuropathy may mask angina, the warning chest pain for heart disease and heart attack.
As we have discussed above,Nerve damage from diabetes can cause you to lose feeling in your feet. You may not feel a cut, a blister or a sore. Foot injuries such as these can cause ulcers and infections. Serious cases may even lead to amputation. Damage to the blood vessels can also mean that your feet do not get enough blood and oxygen. It is harder for your foot to heal, if you do get a sore or infection.
Diabetic Foot Care CausesSeveral 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
Exams and TestsMedical 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 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 HomeA 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
PreventionPrevention 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