Definition

An ulcer of the foot is an open wound that proves challenging to heal or may recur over an extended period. The term "ulcer" originates from Latin, meaning "sore," while "pedis" refers to "foot." This condition arises due to damage to the skin and tissues of the foot. Common symptoms include swelling, burning sensations, and pain at the wound site.

Foot ulcers represent a significant global health issue, with an estimated annual occurrence affecting approximately 4 million individuals. They typically result from foot injuries compounded by nerve damage and circulatory problems.

Foot ulcers can be categorized by their appearance, location, and effects on the skin:

• Venous ulcers (stasis ulcers) affect the lower leg, below the knee, often seen in individuals with a history of leg swelling and venous blood vessel disorders. Damage or blockage of the venous blood vessels can lead to pooled blood and slow-healing open wounds.
•  Neurotrophic ulcers (diabetic foot ulcers) commonly occur on the soles of the feet in people with diabetes due to nerve damage causing sensory disturbances. Individuals may not feel injuries like cuts or cracks on their feet, which can go unnoticed and untreated, eventually leading to foot ulcers.
• Arterial ulcers (ischemic ulcers) can develop anywhere on the foot in individuals with poor circulation. Circulatory disturbances in the blood vessels hinder the healing process of skin and tissues due to reduced blood supply, thus precipitating this type of ulcer.

Causes

There are numerous potential causes for the onset of foot ulcers, including:

• Neuropathy (peripheral nerve damage) due to diabetes.
• Cellulitis, is a bacterial skin infection.
• Injuries to the foot or toes.
• Poor circulation (blood flow), is caused by various conditions.
• Peripheral artery disease.
• Abnormal foot shape.
• Unusual walking patterns that exert excessive pressure on a specific part of your foot or toes.
• Prolonged pressure on the skin and excessive friction, such as rubbing of your feet or toes against your shoes.
• Foot deformities, such as hammertoe, mallet toe, and claw toe.
• Raynaud’s phenomenon, is sudden episodes of decreased blood flow to the hands and feet.
• Bone or muscle disorders of the foot, such as fractures or severe joint inflammation.
• Venous blood vessel disorders, like venous insufficiency.
• Skin cancers, such as squamous cell carcinoma.
• Hypertension.
• Inflammatory diseases including vasculitis, lupus, and scleroderma.
• Infections like herpes simplex, leprosy, HIV, and Epstein Barr virus.
• Genetic disorders like Charcot Marie Tooth disease.

Risk factor

Risk factors for foot ulcers include:

Foot ulcers can essentially occur in anyone, but the risk may be higher for:

• Individuals of Black, Native American, and Hispanic descent.
• Older adults.
• Smokers.
• Alcohol consumers.
• Those with a history of foot ulcers.
• Individuals with gait abnormalities.
• Wearing ill-fitting shoes.
• Suffering from other medical conditions such as:
• Diabetes.
• Circulatory disorders.
• Heart disease.
• Obesity.
• Foot deformities like bunions or hammertoes.
• Kidney disease.
• High cholesterol levels.
• Hypertension.

Symptoms

Symptoms of a foot ulcer can manifest as an open wound on the skin, taking various forms. In cases of pedal ulcers, the wound may resemble a depression or pit. These ulcers can exhibit a range of colors, including:

• Yellow.
• Pink.
• Red.
• Grey.

If an ulcer appears black, it indicates tissue cell death, known as necrosis or gangrene.

The size of a foot ulcer can vary, starting as small as 1 centimeter (approximately the size of a pea) and potentially enlarging to cover the entire foot if left untreated. The depth of the ulcer can also fluctuate. Various classification systems exist to determine the severity of an ulcer, such as The Wagner Diabetic Foot Ulcer Grade Classification System, which categorizes ulcers into six stages:

• Grade 0: Intact skin (no damage).
• Grade 1: Superficial ulcer, involving only the epidermis (outer layer of skin).
• Grade 2: Ulcer extending into the dermis (deeper layer of skin).
• Grade 3: Ulcer extending into tendons or joints, with visible bones.
• Grade 4: Localized gangrene (necrosis) of the toes or forefoot.
• Grade 5: Extensive gangrene affecting the entire foot.

As a foot ulcer progresses, you may notice changes in the skin, such as dryness, cracking, scaling, redness, or the development of a rash.

If the ulcer continues to worsen, it may become wider and deeper. In advanced stages, symptoms may include the formation of calluses, a hardened ring around the ulcer, the presence of pus or fluid (which may be found on your socks when removed), indicating possible infection, discoloration to a brownish hue, and a foul odor.

Diagnosis

In diagnosing a foot ulcer, the doctor will begin by interviewing with you. They will inquire about the symptoms you have experienced, when they first appeared, where they are located, the progression or changes in the appearance of the ulcer, and identify any risk factors that may have contributed to the development of the ulcer.

Following this, a physical examination will be performed to directly assess the appearance of the ulcer, evaluating its depth, edges, and color. The doctor may also palpate the arterial blood vessels in your foot and ankle to assess for abnormalities in pulse pressure. Sensory nerve examination using a Nylon Monofilament may also be conducted to evaluate nerve function in the sole of your foot. During this test, a thin Nylon wire will be pressed against the sole of your foot. If you can still feel its touch, it suggests that the sensory nerves in your foot are functioning properly.

Additionally, the doctor may recommend several other diagnostic tests, such as:

• Wound culture involves sampling a small amount from the ulcer to determine the type of bacteria present if infection is suspected.
• Blood tests, to detect evidence of infection in the bloodstream or identify underlying conditions.
• Assessment of blood flow, such as Doppler ultrasound of the arteries and ankle-brachial pressure index tests, can aid in confirming the diagnosis.
• X-rays, CT scans, or MRI scans to assess for underlying bone damage beneath the ulcer.

Management

The management of foot ulcers aims to heal the wound and alleviate pain. Your treatment plan will be tailored individually based on the underlying medical conditions causing the ulcer. If the root causes of the foot ulcer are not addressed, there is a risk of recurrence after treatment.

There are both surgical and non-surgical approaches to managing foot ulcers. Non-surgical treatments may suffice for early-stage ulcers. More severe ulcers, especially those that are infected, may necessitate surgery.

Non-surgical management includes:

• Wound care by maintaining cleanliness, wound moisture, and covering the ulcer.
• Administration of antibiotics and antiplatelet medications.
• Use of prosthetics or orthotics.
• Offloading pressure from the affected area using casts, shoes, or specific support devices. You may need to use crutches or a wheelchair. This method is called nonsurgical off-loading.
• Elevating the foot above the body's surface.

Surgical management includes:

• Debridement (removal of infected tissue).
• Correction of foot deformities.
• Plantar exostectomy (removal of part of the foot's sole).
• Achilles tendon lengthening.
• Metatarsal osteotomy (cutting and realigning the big toe metatarsal bone).
• Bone cutting or removal.
• Tenotomy (removal of scar tissue).
• Reconstructive surgery using skin grafts.

Complications

If left untreated, foot ulcers can lead to complications such as:

• Increased size and depth of the wound.
• Infected ulcers.
• Reduced function in the foot and, in some cases, may even require amputation.

Prevention

Several preventive measures can help avoid the development of foot ulcers, including:

• Managing underlying conditions. Proper control of blood sugar, cholesterol, and triglycerides can reduce the risk of foot ulcers.
• Check your feet daily for any wounds, cuts, or calluses.
• Maintain foot hygiene. Wash your feet daily with warm water and dry them thoroughly, especially between the toes.
• Apply lotion to the tops and bottoms of your feet to prevent dryness.
• Cut your toenails straight across.
• Avoid going barefoot. Always wear socks and shoes to prevent stepping on something and injuring your feet.
• Ensure your shoes fit well and wear soft socks to avoid blisters.
• Exercise regularly to improve blood circulation, which is crucial for fighting infections.
• Quit smoking.
• If you have calluses or corns, consult your doctor on how to care for them.
• If overweight, follow a weight loss plan.
• Controlling foot temperature can prevent ulcers in diabetic patients.

When to see a doctor?

Consult a doctor if you experience symptoms of foot ulcers, such as open wounds on the feet that are difficult to heal.