Wound Care: Moving Toward HealingPage 7 of 13

5. Diabetic Foot Ulcers

Approximately 85% of all amputations are preceded by a diabetic foot ulcer and more than half of these amputations could have been prevented with proper footwear and effective nail and foot care (Mutch & Dewar, 2015). The importance of patient education cannot be stressed enough in reducing the risk of amputation. Patient and caregiver compliance for prevention is the main defense against amputation. Multiple areas to assess in the diabetic patient include glucose control, smoking, obesity, impaired vision, sensation in the extremities, foot deformity and callous formation, arterial insufficiency, and poor footwear that does not provide adequate support or protection.

A diabetic foot ulcer is caused either by peripheral neuropathy or by peripheral vascular disease resulting from diabetes mellitus (Schub & Schub, 2017). A diabetic foot wound presents on the plantar surface of the foot or toes and results from walking on a foot with lack of sensation. Ulcers can also develop as blisters from poorly fitted shoes, walking barefoot, or walking on a hot surface that results in a burn. The wounds can be partial or full thickness and infections are commonly noted.

These patients usually do not have feeling in their feet due to neuropathy, and may have had the wound for a long time before it was noticed or acknowledged. Diabetic foot wounds are the most common complications of diabetes mellitus, affecting 15% of diabetics at some point in their life (Schub & Schub, 2017). The ulcers usually start small but over time and with lack of care, become larger, and often are surrounded by dry and cracked skin. A surrounding callous may have built up as the body tries to protect itself and the wound.

Assessment and Characteristics

Diabetic peripheral neuropathy is a result of nerve damage caused by high blood sugars that effect the nerves of the legs and feet. High blood sugars interfere with the ability of the nerves to transmit signals to each other. Patients often feel tingling, numbness, or pain starting in their legs and feet, and it can lead to their hands. Neuropathic changes associated with diabetes affect sensation, balance, and gait.

Assess the patient’s ability to feel sensation in their feet using the monofilament test—or lightly touching the patient’s feet while their eyes are closed—to quickly determine sensation. Many wounds results from trauma to the foot of which the patient is unaware. The source of the trauma could be as simple as a small pebble in the shoe, stepping on a nail, or simply wearing shoes too small or too big. A lack of daily foot inspection with the lack of sensation can result in the formation of a new wound.

When a callus develops, it is acting as the body’s natural way to protect itself by making the skin stronger around the injury. However, these callus areas can lead to the development of more wounds. An area of callus can become sharp and hard enough to cause damage to surrounding tissues. With lack of care, the callus tissue can become so hard that it is as if a small stone is under the skin; naturally, this can begin to damage the surrounding skin. It is imperative the callus be removed by a podiatrist skilled in wound care to help prevent further injury or tissue breakdown. Most calluses develop around a wound to help protect the area. Often, areas of undermining or tunneling occur under the callus.


Diabetic wounds can quickly become larger and deeper in patients with neuropathy. All diabetic patients should have a hemoglobin A1c (HgA1c) drawn to assist in diabetic management and patient education.

Diabetic foot wounds must be palpated to determine the depth of the wound, tunneling, undermining, and whether the area palpates to bone. Always palpate the wound with a swab to determine the level of tissue damage. When the callus is debrided, the wound itself may become larger; this is not necessarily a bad thing because with the dead skin cells removed there is room for the new skin cells to begin to grow and heal the wound.

Educate the patient that new healthy skin will not, and cannot, grow if dead skin cells are blocking the area. Explain this benefit of wound debridement in simple language: “Removing the old tissue will allow room for the new skin cells to grow.” Or offer the analogy of a flower growing through a sidewalk. The flower (new skin) will never be able to grow properly unless we remove the sidewalk (dead skin) and give it room.

Diabetic foot wounds often present with signs of infection; often it is not until diabetic patients experience symptoms of infection that they seek medical attention. If there is purulent drainage from the wound, perform a wound culture (if available) to help in selecting the appropriate antibiotic. An x-ray of the injured foot will help rule out osteomyelitis. Some physicians may request an MRI or CT scan in addition. Frequently the patient is unsure of when the wound first developed, or they do not feel comfortable telling the clinician when the wound occurred.

Patient and Caregiver Compliance

The patient and caregiver need to be aware how serious an infection is and that it can lead to the risk of amputation without compliance to a proper plan of care. Ideally, the goal for HgA1c is under 7.0 and this value can be used to encourage patient compliance in tracking progress, or the lack thereof.

Diabetic foot ulcers are very complex, for the reason that many diabetics with wounds are often non-compliant. Blood glucose control education must be constantly reiterated to caregivers and patients to assist with progressive wound healing. If the patient does not have a history of compliance with their medication or blood glucose control, education on the effects of wound healing should be done each visit and literature can be given as well. Encourage achieving a blood glucose control value of under 150.

A simple explanation to encourage compliance is to inform the patient that the body’s healing processes diminish when proper blood glucose is not managed. Explain that the body is focused more on combating the high blood sugar than healing the wound. Wound healing for diabetic patients requires as much effort on the patient’s part as on the clinician. Without patient assistance, healing will not occur. It is important to make patients aware that they must do their part in helping their body heal; they must take responsibility for caring. As healthcare providers, we do our part, but patients must do theirs.

We may only see patients once or twice a week and we cannot control what they are doing when we are not in the home. Look for triggers to encourage accountability from the patient. For example, they may want to go the beach or into the pool but the wound is not healing; encourage them to assist in the process so they will be able to swim in the near future. Goal setting can help encourage patient and caregiver compliance. Patient and caregiver buy-in will make the wound healing process more productive and effective. Caregivers and patients must be aware of this and reminded at each visit.

Nutrition is an important factor for basic blood sugar control and for wound healing. A diabetic educator referral is valuable to assist with healthy nutritional choices, possibly carbohydrate-counting lessons, and education on protein choices for wound healing. Encourage visits to the eye doctor, to assess the effects of diabetes on vision, and to the endocrinologist for emphasis on overall health and the necessity for blood sugar control through appropriate medication. Smoking cessation should be a topic for all members of the household. People with diabetes who smoke are more likely than nonsmokers to have trouble with insulin dosing and with controlling their disease (CDC, 2017).

Off-Loading and Footwear

Patients and caregivers must be educated on the importance of off-loading to allow the new skin cells to heal the wound without continued trauma to the area. A basic surgical shoe may be all that is required to assist in keeping pressure off the wound area. Alternately, an orthotist can properly measure and fit for specially made shoes to ensure adequate off-loading. These require a doctor’s prescription and having obtained assurance that the patient is willing to wear the shoe. To prevent any future complications, encourage regular visits to a podiatrist trained in wound care for nail trimming and foot assessment as well as reassessment of off-loading shoes.

Be sure to question patients about how often, indeed whether, they are wearing their off-loading device. Inspect the device or shoe for signs of wear and tear. When a patient is not wearing the required off-loading device or shoe, there will be a delay in wound healing, and additional wounds may develop.

Adhering to basic hygiene and behavioral changes will assist the patient and caregiver in prevention. Feet should be washed daily! Encourage keeping the toes clean and with no debris in between. Patient or caregiver is to perform a daily foot examination between toes, check socks to look for draining blisters, and check foot temperature as a sign of infection. Patient should always wear shoes, never walk barefoot, even in the house, and check water temperature before entering the tub.

Patients should not cut a callus—and must trim nails carefully if they do it at home. While it is important to wear socks, avoid tight-fitting socks that may impact circulation. When buying shoes, ensure the shoe is a proper fit and inspect feet daily for any injuries. A mirror can be used to inspect bottoms of feet and between toes if the patient lives alone.

When buying new shoes, the patient should not wear them later in the day because feet swell as the day wears on. When patient have purchased new, properly fitted shoes, instruct them not wear the new shoes for more than two hours and not to wear the shoes without socks.

During the winter months, encourage the patient and caregiver not to use heaters or heating pads. With lack of sensation in the feet, it is easy to cause a burn without the patient being aware of the damage. This is seen quite commonly during cold months; unfortunately, some patients do not know they are being burned until they smell the skin burning.

Overall, education on blood glucose control, lifestyle changes, off-loading, meticulous wound care and weekly wound care center visits must be emphasized with each visit and given consistent reminders.

Education for diabetic patients must be tailored to the individual patient and the support system needs and priorities. Our patients may not develop the skills to prevent a DFU or its complications but education can aim toward early problem identification and seeking of help from a healthcare professional.

Discuss and set goals, review them at every visit, look for barriers to patient and caregiver learning, and use multiple teaching tools to assist with education. Continually emphasize the importance of basic foot care and daily foot inspection. You can ask the patient and caregiver what-if questions to assist in building problem solving skills. For example: What if you find a callus on the bottom of your foot? What if you notice blood on your sock at the end of the day?

Use questions to encourage teachable moments. Supplying the patient and caregiver with community resources to provide additional educational outlets and support groups can also encourage interaction with others in the community and provide needed social support.

Case: John

John is a 63-year-old male who has neuropathy in both feet, healing open blister with callus buildup from ill-fitting shoes on plantar aspect of right great toe. The open wound measures 1.7 cm x 1.5 cm with a moderate amount serosanguinous drainage, no odor, no complaints of pain, no feeling to the area, foot/leg warm but not hot, and slight temperature difference from left leg. Patient states he does not walk barefoot but has worn-out slippers at the bedside. He has seen the wound center doctor in the past but his insurance changed over the last several months so it has been difficult to be consistent. John lives alone and his blood sugar has not been well controlled lately. The patient has an appointment this week in the wound center to see a physician for callus debridement but when you arrive at John’s home the wound appears to be infected.

What are your first steps? Cleanse wound with normal saline, measure and assess the wound bed. Palpate the wound to determine depth—see if it palpates down to bone or is undermining. Cleanse thoroughly, take wound culture (if available). Inform patient this is to ensure appropriate antibiotics are prescribed if infected. If there are signs of infection and wound palpates to bone, send patient to emergency department. (This wound bed is clean with no s/s infection.)

Diabetic Foot Ulcer

Photo of Diabetic Foot Ulcer

Source: T. Sbriscia.

The sooner the patient is seen, the greater the possibility to reduce the chance of amputation. When the patient arrives to the ED: clean and culture, begin IV antibiotics, and suggest an x-ray (and possibly MRI ) of the foot to rule out osteomyelitis. In this case, topical treatment can be done to assist in preventing infection as the wound bed is clean.

Check if patient has allergies to silver. If not, utilize an antimicrobial product (silver alginate) to cover the open wound and absorb drainage. Patient must be seen by a podiatrist with wound training. Debridement of callus is needed and further treatment to assist in wound closure. If osteomyelitis is present, further treatment will be discussed with patient. Education for patient and caregiver will be to review appropriate off-loading and the necessity to prevent further damage, provide the proper foot wear and instructions, and encourage blood glucose control to assist in healing.

John’s case is common in the diabetic population and can be difficult because patient compliance has been dictated in part by his insurance situation. Education for this patient includes recognizing warning signs of infection and complications to prevent amputation—regardless of his insurance status.