What is Foot Ulcer?
Foot ulcers, or open sores on the foot, are becoming increasingly common health problems. They’re a main reason why some people, especially those with uncontrolled diabetes, might need to have a foot or leg amputated. In fact, if you have diabetes, there’s more than a one in three chance at some point in your life you’ll develop a foot ulcer.
These foot ulcers are not only painful but also dangerous. They’re responsible for about two-thirds of all amputations in the US that aren’t due to an injury. Adding to the danger, people with diabetes who get foot ulcers are often prone to infections, which can put their entire limb at risk.
What Causes Foot Ulcer?
Foot ulcers, or open sores on the foot, can form and worsen due to many factors working together. These factors could include problems with your blood vessels, nerve damage, structural issues in your foot, and changes to the soft tissues of the foot.
The problems with blood vessels can be of two types: large blood vessels (such as in the heart, brain, and peripheral arteries like the ones in your legs) and small blood vessels (like arterioles and capillaries). Peripheral arterial disease (PAD) is a condition that often affects the arteries in the legs, especially the ones around the lower leg and foot. This disease is characterized by a buildup of fatty deposits, or plaque, inside the arteries, which can hinder the healing of foot ulcers. Certain conditions and lifestyle habits such as diabetes, smoking, high blood pressure, and high cholesterol can increase the risk of developing PAD and, consequently, foot ulcers. It’s important to note that patients with both diabetes and PAD have a higher chance of needing a lower limb amputation.
Blood sugar levels that are too high are linked to increased levels of a substance called thromboxane A2. This substance causes blood to clot more easily and can promote narrowing of blood vessels, which can then lead to blockages.
In patients with diabetes, where blood sugar control can be challenging, the small blood vessels or capillaries can also be affected. This can result in changes in blood flow and an increase in the leakiness of these blood vessels. One of the leading causes for these changes is believed to be a condition called “endothelial dysfunction”, where the inner lining of small blood vessels start to malfunction. The body naturally produces a substance called “nitric oxide” which helps to keep blood vessels wide open and regulate blood pressure. However, patients with diabetes often have a decreased level of nitric oxide, leading to narrower blood vessels and higher blood pressure. This lack of blood flow and oxygen can ultimately lead to the formation of ulcers, as it hampers the healing process.
Peripheral neuropathy is a condition that involves the gradual loss of nerve fibers, which could include sensory, motor, and automatic nerve fibers. This could result in a complete loss of feeling, often starting at the ends of the body, like toes. At advances stages of this condition, patients may not even be aware of small injuries. Motor neuropathy can cause imbalance in the muscles, leading to increased pressure on certain parts of the foot and the breakdown of tissue. Nerve damage can also cause less blood to reach the soft tissues of the foot, depriving them of the nutrients and oxygen they need.
Structural deformities in the foot, like bunions, hammertoes, rigid big toe, and Charcot foot (a foot disorder caused by nerve damage) can also increase pressure and lead to ulcers. Furthermore, a decrease in the soft tissue density or thinning of the cushioning fat layer in the foot can also increase the risk of foot ulcers.
Risk Factors and Frequency for Foot Ulcer
Foot ulcers are a global health issue that have become more common because of the rise in diabetes. It’s estimated that over 6% of people worldwide have foot ulcers, and they are believed to be more prevalent in males. They are especially common in individuals with type-2 diabetes compared to those with type-1 diabetes.
- Foot ulcers occur most often in older individuals.
- They are more common in people who have had diabetes for quite some time.
- Oftentimes, these individuals also have other health issues such as high blood pressure and diabetic eye disease.
- People with a higher body mass index are more likely to develop foot ulcers.
- Smokers also have a higher risk of getting foot ulcers.
Signs and Symptoms of Foot Ulcer
When dealing with a patient who has an ulcer, it’s crucial to gather full information about their medical, surgical, and social history, allergies, and current medication. An in-depth evaluation of the ulcer and its surrounding tissues includes steps like measuring the wound, biopsy, and cultures. These help to understand the wound better.
In addition to these, the appearance and smell of the wound also tell a lot about its status. For example, a fruity odor might suggest a pseudomonas infection. Things to watch out for when looking at the wound include redness, swelling, any fluid discharges, crepitations, or the presence of abscesses. Also, it is crucial to inspect the wound edges to see if there is any formation of hyperkeratotic tissues, which obstructs tissue healing. This condition can result from too much stress on the tissue, implying that the focal pressure needs an evaluation. Removal of the trapping fluid in hyperkeratotic tissue improves wound healing.
The character of ulcer bases provides valuable insights. A black, non-viable ulcer base implies either peripheral arterial disease or infection. Fibrotic-base ulcers have a stringy white to yellowish appearance that hinders the formation of granulation tissue. In contrast, red beefy-appearing granular-base ulcers show good healing potential. It’s crucial to probe any wound tracking into sinus tracts, as they can signal a deeper infection.
Every clinic visit needs to include the monitoring of quantitative measurements. Comparisons of wound dimensions (width, length, and depth) over time help evaluate wound contraction. In cases of infection, ulceration discharge cultures enable targeted antibiotic therapy. A biopsy is necessary for long-lasting ulcers to eliminate any chances of malignant changes.
Testing for Foot Ulcer
If you’re experiencing symptoms such as pain, redness, heat, and swelling at the site of a wound, your doctor may suspect an ulcer infection. Other symptoms like fever, nausea, vomiting, diarrhea, and chills could also indicate a body-wide infection. To make a proper diagnosis, some blood tests may be conducted, including checking creatinine, bicarbonate, a comprehensive metabolic panel, erythrocyte sedimentation rate, C-reactive protein, and a complete blood count.
Using imaging techniques like X-rays or MRI scans can also be valuable in evaluating your condition. These methods can help in assessing if there is bone inflammation (osteomyelitis) or a dangerous type of infection known as gas gangrene. CT and bone scans might occasionally be used to investigate changes in bones.
When dealing with ulcers, it’s also essential to check the blood flow in your vascular system. This can be done through a clinical examination of the temperature, skin color, signs of skin thinning, hair distribution, and feeling the pulse in your foot arteries. A method called Doppler ultrasonography can be helpful if the pulses in your feet are hard to feel. Another useful test is the ankle-brachial index, which measures blood flow in your legs.
Depending on the results of the ankle-brachial index, your doctor might suggest further tests like a magnetic resonance angiography (MRA), an arterial duplex ultrasound, or an arteriogram to check for blockages in your blood vessels. It should be noted that ulcers related to poor blood flow (arterial ulcers) are often painful and typically develop on a distant part of your extremity. But those caused by diabetes tend to be painless due to nerve damage (neuropathy) and usually occur on areas where your body puts weight.
A test of nerve function (an electromyography test) can be done alongside a nerve conduction velocity test to evaluate peripheral neuropathy, which is nerve damage often associated with diabetes. Imaging is key to ruling out issues like structural deformities in ulcers. A device that measures pressure on the bottom of your foot can identify high pressure points and underlying bone deformities.
All these evaluations and tests play a critical role since abnormalities in the bone structures of your foot, poor blood flow, or nerve damage may increase the risk of developing ulcer.
Treatment Options for Foot Ulcer
There are many ways to treat long-lasting, non-healing ulcers – open sores or wounds on your body that don’t heal well. One common treatment is something called debridement. It’s a process that removes unhealthy tissue from the wound to promote healing. There are four primary ways of doing this.
First, surgical debridement involves using surgical tools like scalpels to carefully cut away the non-healing tissue. Second, enzymatic debridement applies a medicine called collagenase to the ulcer that breaks down collagen, a protein in skin, to aid in healing. Third, mechanical debridement involves using a technique of wet-to-dry dressing, where dressings are moistened then allowed to dry between changes. When removed, the dressing takes with it the non-healing tissue. Finally, biological debridement uses the body’s own process or creatures like medical-grade maggots to clean the wound.
Another key part of ulcer treatment involves lessening pressure on the ulcer, known as offloading. This could be done by using orthopedic shoes, crutches, a wheelchair, or a specific cast to avoid putting weight on the ulcer.
Medical science also offers advanced methods like bioengineered tissues to help heal ulcers. These are growing, living tissues added to the wound to speed healing or deliver substances that promote healing. Also, certain types of grafts – transplanting healthy tissue to the wound site – can play a crucial role in treating ulcers.
Negative pressure wound therapy is another method that can be handy for treatment. It’s a medical procedure involving the use of a vacuum-like device to enhance healing – this technique helps reduce bacteria and promotes healthy tissue growth at the base of the ulcer.
Hyperbaric oxygen therapy can also be beneficial in ulcer treatment. In this process, you breathe pure oxygen in a special chamber. Healing might be sped up because of a greater amount of oxygen reaches the blood and the wound.
Finally, surgeries could be performed to correct any underlying issue causing the ulcer. Procedures like correcting a tendon length or removing bony growths can make a big difference.
For ulcers caused by peripheral neuropathy – nerve damage often in hands and feet – there are options too. Usage of things like light therapy or topical nitric oxide boosts blood flow to affected nerves to help treat the ulcers. You might also be recommended certain supplements or oral medications to help manage the symptoms.
What else can Foot Ulcer be?
When a doctor is trying to figure out what’s causing a foot ulcer, they may consider various possibilities. This could include specific types of skin cancer and other skin conditions. Some of the conditions that might be considered are:
- Squamous cell carcinoma
- Basal cell carcinoma
- Melanoma
- Kaposi sarcoma
- Lymphoproliferative malignancies (a type of blood cancer)
- Sarcoidosis (a disease involving abnormal collections of inflammatory cells)
- Necrobiosis lipoidica (a skin condition that usually affects the lower legs)
- Bullous diseases (conditions characterized by blistering of the skin)
- Pyoderma gangrenosum (a rare skin condition that causes large, painful sores)
What to expect with Foot Ulcer
The chances of recovery from infected foot ulcers heavily depend on numerous factors, such as the patient’s overall health and the treatment methods used. Unfortunately, the general outcomes of such infection are not very encouraging, with a 17% chance of needing to amputate the lower limb and a 15% mortality rate within a year. Furthermore, less than half (44%) of the patients manage to heal within a year.
The patient’s journey to recovery tends to be more straightforward if there are no multiple or chronic foot ulcers, or if there isn’t any condition causing restricted blood flow to the limbs.
Despite these statistics, it’s important to note that you can greatly improve your chances of recovery by strictly following the treatment plan provided by your healthcare team and managing your cholesterol and glucose levels effectively.
Possible Complications When Diagnosed with Foot Ulcer
Foot ulcers in people with diabetes are the primary reason for non-accident-related leg amputations. Roughly 35.4% of hospitalized diabetic patients with foot ulcers end up having a leg amputation. Several factors can predict the likelihood of a leg amputation. These include how long the ulcer has been present, if the wound is infected, a Wagner grade 4 or higher, limited blood flow to the extremities, an unusually high protein level in the urine, an infection in the bone, and a higher than normal white blood cell count.
Factors that can predict a leg amputation:
- Duration of the ulcer
- Presence of wound infection
- Wagner grade 4 or more severe
- Peripheral arterial disease:
- High protein levels in Urine (Proteinuria)
- Bone infection (Osteomyelitis)
- High white blood cell count (Leukocytosis)
Preventing Foot Ulcer
Most of the time, care for foot ulcers happens outside the hospital – meaning, patients need to take care of their sores at home. This is why learning about foot ulcer care is so important. Patients need to know how to change their bandages every day. They should also understand why it’s important to keep the bandage dry, clean, and undisturbed.
Patients should also know how to use special tools that can help them get around without hurting their foot. These tools include a medical boot (also known as a CAM walker), a special shoe for foot injuries, crutches, and walking sticks. Using these can help the foot ulcer heal and prevent further damage.
