Foot Infections

What causes an infected foot?

Foot infections occur when bacteria enter the foot in some way, either through a wound or through the skin. An infected foot can be painful and hinder mobility, but it can be difficult to treat because the infection’s underlying cause can be difficult to identify.

Foot infections are common because foot injuries are common. The ground is full of dangers and sharp objects, which can pierce the skin and create an opportunity for bacteria to enter the body. Plus, some microorganisms, like the bacteria that causes athlete’s foot and toenail fungus, flourish in this environment, and some conditions may increase the risk of foot infection. Wearing socks and shoes can create a moist environment, where bacteria and fungi can flourish, and walking around barefoot can cause injuries that lead to eventual infections. The only way to prevent a foot infection is through proper foot maintenance and by seeking medical attention immediately after injury.

What are the types of foot infections?

Foot infections are common, which means there are several types of infection. Some are caused by common fungi and bacteria, many of which are part of the skin’s natural microbiome, while others are caused by open wounds. Below, you’ll find categories for the most common types of foot infection.

• Fungal – These are the most common types of foot infections. Fungal infections occur when the feet remain damp for prolonged periods, such was while working in wet conditions or sweating. This causes athlete’s foot, a very common but contagious fungus that can spread through contact with towels, clothing, and floors. Nail fungus is also very common.
• Bacterial/Wound-Based – Cracks and cuts in the skin provide an opportunity for bacteria to enter the body. These bacteria may be on the floor, but it may also be part of your skin’s natural microbiome. While some wounds may be caused by dangers on the ground, they can also be caused by ingrown toenails and damaged plantar warts.
• Diabetic – People with diabetes have an increased risk of foot infection because high blood sugar can damage the skin, blood vessels, and nerves in the feet. Additionally, diabetes may reduce blood flow, which can slow the healing process and increase the risk for developing serious foot infections. Diabetic foot infections always require a visit to the doctor.
• Post-Surgical Infection – While rare, complications from foot surgery can result in foot infections. The risk for developing an infection is less than 1 percent in people who are healthy, as antibiotics are typically provided before surgery to reduce the risk. However, having diabetes or other immune system conditions can increase a person’s risk, as can smoking.

What does an infected foot look like?

Foot infections can have a wide range of causes, which means symptoms will typically vary. However, there are a few common symptoms you may be able to identify. Some combination of the experiences listed below will generally occur regardless of your foot infection’s cause.

• Persistent pain or itching
• Heat that radiates from a previous wound or abrasion
• Swelling
• Difficulty walking
• A foul smell
• Wounds that do not heal
• Pus
• Discoloration

If your foot is severely discolored and consistently oozing, your infection is serious. These are some of the most dangerous symptoms of an infection and require a doctor immediately. Though they can be quite varied in appearance, here is a picture of a typical foot infection.

When should you go to the doctor for an infected foot?

While fungal infections are easily treated with over-the-counter medications (antifungal sprays and creams), some will require medical or surgical treatment. If your infection causes swelling, heat, a foul smell, and makes walking difficult, you will need to see a doctor for antibiotic medication. However, if you have more serious symptoms, you should seek emergency medical treatment. This includes any of the following experiences.

• Red Streaks – Red streaks, or a slow-moving red line, can indicate infectious lymphangitis. This condition occurs when the infection invades the lymphatic system or bloodstream. This can quickly cause infection throughout the body and requires a doctor’s help immediately.
• Fever and Chills – This can indicate that the infection has spread. Seek emergency medical help immediately.
• Crackling Noise – This is a symptom specific to gangrene, or localized body tissue decomposition. This symptom is typically accompanied by severe discoloration, swelling, and a foul odor. In many cases, gangrenous appendages must be amputated.
• Quickly Spreading Swelling/Redness – These symptoms may indicate cellulitis, a severe form of infection. This occurs when a bacterial infection reaches deeper layers of the skin. This infection can easily spread to the lymph nodes and bloodstream. If not treated quickly, the condition may become life-threatening.

If you have diabetes, you should visit the doctor as soon as you suspect a foot infection, as you are predisposed to developing a more serious condition. Remember that seeing a doctor at the first signs of a serious infection can drastically reduce the risk of complications.

What are the best antibiotics for a foot infection?

The type of prescribed antibiotic will depend on the progression and severity of your infected foot. Patients with mild infections can be treated with oral antibiotics, like cephalexin, dicloxacillin, amoxicillin-clavulanate, or clindamycin. A more severe infection is typically treated intravenously with ciprofloxacin-clindamycin, piperacillin-tazobactam, or imipenem-cilastatin. None of these antibiotics are available without a doctor’s prescription.

While the above medications are the most popular for treating foot infections, the type of antibiotics that will work for your foot will depend on the infection’s cause, your body, and your symptoms. Unless you are experiencing a common, low-risk fungal infection, like athlete’s foot, you should always seek a doctor’s help if you believe you have an infection.

Are there other treatments for an infected foot?

As mentioned, some fungal infections can be treated with over-the-counter antifungal medication. If you have a bacterial infection, antibiotics will typically do the trick, especially if you visit the doctor at the first signs of infection. However, there are a few more severe treatments that may be necessary if the infection is allowed to spread.

• Excision – This can be an effective treatment if the infection has not spread but was not treated or disinfected in a timely manner. Surgical excision of all dead and infected skin and bone can prevent full amputation and infection spread. In less severe cases, this treatment consists of draining pus and removing all necrotic and infected tissue.
• Amputation – This treatment is necessary if an infection becomes gangrenous. Amputation can stop the infection from spreading to other parts of the body, but it dramatically changes a person’s life.
• Vacuum-assisted closure – This type of therapy is common for diabetic foot infections that do not heal on their own. The procedure helps the wound heal. During a vacuum-assisted closure, a device decreases air pressure around the wound, which can help it heal more quickly.

Remember that, if medical attention is sought reasonably quickly, these more serious foot infection treatments are usually avoided. Talk to your doctor about which treatment options are best suited for your body.