Diabetic Ulcer: Improving Healing Success for Feet and Legs

A diabetic ulcer is a type of skin sore that often occurs on the feet, toes, or legs. It can occur in people who have type 1 diabetes but is more common with type 2 diabetes.

Diabetes can cause nerve and blood vessel damage in the feet, which can reduce sensation and make injury less noticeable. Diabetes can also cause wounds not to heal well. These factors can lead to the development of foot ulcers in people with diabetes.

The lifetime risk of developing a foot ulcer for a person with diabetes is estimated to be 19–34%, with a recurrence rate of 40% within one year and 65% within five years.

This article will discuss what causes foot ulcers in people with diabetes, the stages of ulcer formation, the importance of treating ulcers, treatment for ulcers by severity, signs an ulcer is healing, and foot care and walking assistance.

Why Do Diabetic Ulcers Form?

Diabetes can cause damage to blood vessels, including the tiny blood vessels that supply the leg nerves. This can result in peripheral neuropathy (burning, pain, or numbness in the feet) and/or reduced pain sensation.

Nerve damage occurs in about half of people with diabetes and commonly affects the nerves in the feet and legs. Some people experience tingling, pain, or numbness, while others have no symptoms. Nerve damage can cause a loss of pain, heat, or cold sensation.

Loss of sensation can lead injuries such as blisters, cuts, calluses, burns, or ingrown toenails to go unnoticed, allowing them to get worse before they can fully heal.

Damage to blood vessels caused by diabetes can also cause poor circulation (peripheral artery disease) and decreased blood flow to the feet (ischemia) and/or skin (microangiopathy). This can hinder wound healing.

The combination of reduced sensation and poor wound healing increases the risk of infection and can lead to the development of ulcers in the feet, legs, or toes.

The ulcers tend to form in areas where there is increased pressure on the skin, such as the heel, ball of the foot, and bottom of the big toe. Ill-fitting shoes can also cause ulcers on the side of the foot.

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Nerve damage can occur in anyone with diabetes, but some factors can increase the risk, including:

• Hard to manage blood sugar levels
• Being older than 40 years of age
• Having diabetes for a long time (particularly if blood sugar is often higher than target levels)
• Being overweight
• Having high blood pressure
• Having high cholesterol
  

Stages of Ulcer Formation in Diabetes

Assessment of an ulcer should include the site, size, and depth of the wound as well as any discharge. The neuropathic and vascular status of the foot should also be assessed.

Foot ulcers due to diabetes can be classified in a number of ways, including the perfusion, extent, depth, infection, and sensation (PEDIS) classification system and the University of Texas (UT) classification system.

PEDIS

PEDIS Grade 1:

• Wound without evidence of purulence (pus) or inflammation
• Uninfected
  

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PEDIS Grade 2:

• Wound associated with two or more signs that suggest inflammation, such as purulence, erythema (redness of the skin), pain, tenderness, warmth, or hardening of the skin
• Extent of the erythema is limited to 2 centimeters (about three-quarters of an inch) or smaller around the ulcer
• Superficial/mild infection without evidence of systemic toxicity or local complications
  

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PEDIS Grade 3:

• Wound associated with moderate infection but without signs of systemic illness
• At least one of the following: erythema larger than 2 centimeters, lymphangitic streaking (red streaks on the skin), spread beneath the superficial fascia (layer of connective tissue right under the skin), deep-tissue abscess, gangrene, and involvement of muscle, tendon, joint, or bone
  

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PEDIS Grade 4:

• Wound associated with severe infection
• Evidence of systemic toxicity or metabolic instability, such as fever, chills, tachycardia (faster than normal resting heart rate), hypotension (low blood pressure), confusion, vomiting, leukocytosis (elevated white blood cell count), acidosis (too much acid in the body), severe hyperglycemia (high blood glucose), or azotemia (abnormally high level of nitrogen waste products in the blood)
  

UT Grade

• Grade 0: Pre- or post-ulcerative or healed wound
• Grade 1: Superficial wound not involving tendon, capsule, or bone
• Grade 2: Wound that penetrates to tendon or capsule
• Grade 3: Wound that penetrates to bone or joint

UT Stage

• Stage A: No infection or ischemia (reduced blood flow to the area)
• Stage B: Infection present
• Stage C: Ischemia present
• Stage D: Infection and ischemia present

Symptoms to Identify 

It is important to inspect the tops, sides, soles, and heels of your feet, and in between your toes daily to check for problems such as:

• Blisters or sores
• Dry, cracked skin
• Bruises or cuts
• Firm or hard spots
• Redness and/or warmth
• Tenderness (which may not be present because of nerve damage)

If you notice any of these problems, see your healthcare provider; don't try to treat them yourself.

Call your healthcare provider right away and don't wait for your next appointment if you notice any symptoms like:

• A blister, ulcer, sore, ingrown toenail, or infected corn
• Dry, cracked skin on your feet
• Change in the color and/or temperature of your feet
• Tingling, burning, and/or pain in your feet
• Pain in your legs or cramping in your thighs, calves, or buttocks during physical activity
• Loss of sensation to touch or ability to feel heat or cold very well
• Change in the shape of your feet over time
• Hair loss on your feet, toes, and lower legs
• Thickened, yellow toenails
• Fungal infection (such as athlete's foot between the toes)
  

Importance of Ulcer Treatment in Diabetes

Foot ulcers related to diabetes can significantly affect quality of life, including physical, financial, and psychological impacts.

Checking feet your every day increases the likelihood you will catch problems early. Early treatment decreases the chances of serious complications.

A multidisciplinary approach to preventing and treating foot ulcers in people who have diabetes may involve multiple healthcare providers, including:

• General practitioners
• Endocrinologists
• Wound care nurses/a wound care clinic
• Podiatrists
• Vascular surgeons
• Infectious disease specialists
  

Treating Diabetic Ulcer by Severity 

Treatment of a foot ulcer depends on the severity of the wound and the extent of the damage. A healthcare provider should perform treatment for foot ulcers.

Superficial Ulcers

If the ulcer only involves the top layers of the skin, treatment typically includes:

• Debridement: This involves cleaning the ulcer and removing dead skin and tissue.
• Dressing: The wound is covered with a dressing to keep it clean and moist.
  
• Cleaning routine: Follow your healthcare provider's directions on how and when to clean the ulcer and apply a clean dressing (typically twice daily). Have someone help you if necessary.
• Antibiotics: If the ulcer is infected, you will be prescribed antibiotics. Take the entire course as directed.
• Off-loading: Keep weight off the affected foot as much as you can. Elevate it when you are sitting or lying down. A cast or other device may be recommended to help take pressure off the area when walking.
• Follow-up: Check in with your healthcare provider at least once a week to make sure your ulcer is healing properly.

More Extensive Ulcers

If the ulcer extends into the deeper layers of the foot and reaches muscle and bone, you will probably require hospital treatment. This treatment may involve:

• Tests: X-rays and laboratory tests may be conducted.
• Debridement: Removal of dead skin and tissue may require infected bone to be removed through surgery.
• Antibiotics: These are often given via an intravenous (IV) line.
• Negative pressure wound therapy: The ulcer is covered with a bandage, and a special vacuum device is applied to help increase blood flow and promote healing.
• Hyperbaric oxygen therapy: A special pressure chamber helps deliver more oxygen to the wound.
  

Severe Damage

If gangrene (dead tissue that may be infected) is present or the ulcer will not heal despite aggressive treatment, amputation of part or all of the foot or leg may be necessary. Gangrene can be life-threatening if untreated.

If there is a severe foot ulcer and poor circulation, a procedure to restore blood flow to the foot may prove necessary.

Regardless of the severity of the ulcer, managing blood sugar is important to help promote healing. Quitting smoking and controlling blood pressure and cholesterol levels are also important.

Signs a Diabetic Ulcer Is Healing 

A healing ulcer closes back over. Even if you think your ulcer is healing, it's important to keep following your treatment plan and checking in with your healthcare provider for monitoring.

Signs of Worsening Ulcer 

Call your healthcare provider if you have signs of an infection or worsening ulcer, such as:

• Pus or extra drainage
• Warmth, redness, or swelling around the ulcer
• Increased pain
• Fever and/or chills
• Increased firmness around the wound
• Odor
• A blue, black, or very white ulcer

Foot Care and Walking Assistance 

It's very important to keep pressure off your ulcer. Walking on it can enlarge it and force your infection deeper into the foot.

You may need to rely on certain devices to protect your foot as the ulcer heals and/or after healing to prevent scar tissue from breaking down and the ulcer from recurring. These may include:

• Special shoes
• Braces
• Casts
• Mobility devices such as a wheelchair

To help prevent foot ulcers:

• Keep your feet clean, dry, and moisturized.
• Check your feet every day.
• See your healthcare provider for any changes in your feet, including calluses, injuries (even minor ones), or ingrown toenails.
• Take a clinical foot examination at least once a year.
• Do not smoke.
• Maintain good blood glucose control and follow an eating plan that is healthy for people with diabetes.
• Use lukewarm water and mild soap to wash your feet every day, then gently dry them (especially between the toes) and apply lotion, petroleum jelly, lanolin, or oil on dry skin (but not between the toes).
• Have a healthcare provider or podiatrist (foot doctor) trim your toenails if your nails are thick or discolored, you need help cutting them, you have poor vision, or you have decreased sensation in your feet.
• If your healthcare provider says it is OK for you to cut your own toenails, soften the nails first by soaking your feet in lukewarm water, cut the nails straight across, and make sure the edge of each nail does not press into the skin of the toe beside it.
• Have your healthcare provider treat corns and calluses.
• Protect your feet from heat. Don't use a heating pad or hot water bottle on your feet and avoid walking barefoot on hot surfaces such as pavement, tiles, or sand.
• Get physical activity every day, even if it's just 10–20 minutes.
• When sitting, elevate your feet.
• Wiggle your toes for a few minutes several times a day.

Footwear is very important for people who have diabetes:

• Wear shoes or slippers at all times (check inside them for anything that may hurt your feet, including rough areas, before putting them on every time).
• When buying shoes, make sure they are comfortable and fit well from the beginning (don't get tight shoes, even if you think they will stretch with use). Try to buy shoes at the end of the day, when your feet are the largest.
• Break in new shoes slowly by wearing them for one to two hours a day for the first week or two.
• Change broken-in shoes after five hours during the day to change pressure points.
• Avoid wearing flip-flops, sandals, shoes with pointed or open toes (like high heels), and stockings with seams.
• Wear clean, dry socks or non-binding pantyhose that are free of holes. Consider socks with extra padding and/or socks that move moisture away from your feet.
• Choose shoes made of leather, canvas, or suede (avoid ones that are made of plastic or other materials that limit air flow to your feet).
• Wear shoes that are easily adjustable with laces, Velcro, or buckles.
  

Summary

Diabetes can cause nerve and blood vessel damage in the feet, which can lead to ulcers. Foot ulcers from diabetes can start mildly, affecting just the top layers of skin, but without treatment, they can become infected and lead to complications, including amputation.

Foot ulcers from diabetes are treated with debridement, wound dressing, and antibiotics. More extensive damage may require surgery to remove dead tissue and/or procedures to promote healing.

Protecting the feet and reducing pressure on the feet through measures such as consistently wearing well-fitting shoes are important for treating and preventing foot ulcers. Managing blood sugar and checking your feet daily are other important ways to prevent the kind of foot ulcers that are associated with diabetes.