Types of foot fungus and how to treat them

If you’ve ever had scaly, peeling, or cracked skin between the toes accompanied by intense itching, you’ve probably experienced a fungal infection of the foot. Or maybe you’ve noticed a toenail that becomes thick and yellowish in color—also most likely a fungal infection. The term foot fungus describes superficial fungal infections that occur on the foot and can affect the skin, hair, or toenails. 

The good news is there are many effective treatments for fungal infections of the foot. There are many over-the-counter (OTC) products including ointments, gels, creams, lotions, powders, or sprays. For more serious infections, a healthcare professional may prescribe antifungal pills or recommend both a topical and oral medicine. Read on to learn more information about the different fungal infections that can affect the foot and what antifungal therapy options are to choose the most effective treatment.

What is foot fungus?

Foot infections can be caused by many different microorganisms. Bacteria can get into a wound, such as a cut or a crack in the skin, and cause a foot infection. Bacterial infections usually cause swollen, painful, and redness, usually accompanied by green or yellow pus. Fungal infections of the foot are caused by different fungi organisms, depending on what type of tissue they infect. Fungal foot infections may appear red, purple, gray or white, and be scaly or flaky. Fungal toenail infections typically begin as a white or yellow-brown spot under the tip of the nail and then cause the nail to thicken and crumble at the edge. If necessary, diagnosis of a fungal infection can be made by a healthcare professional scraping the infected skin and inspecting it under a microscope to determine what type of fungus is causing the infection.

Types of foot fungus

Athlete’s foot (tinea pedis)

Athlete’s foot fungus (also known as tinea pedis) is a fungal skin infection that usually begins between the toes. It is most often associated with athletes because the damp, warm environment in a locker room increases the likelihood of the presence of the fungus—and being barefoot in a locker room allows for easy transmission. The risk of the fungal infection taking hold is increased when feet remain damp or when wearing tight shoes. 

The species of fungi that typically result in tinea pedis are:

• Trichophyton rubrum
• Epidermophyton floccosum
• Trichophyton interdigitale

Signs and symptoms of athlete’s foot include:

• Scaling, peeling or cracked skin between the toes
• Itching
• Inflamed skin that appears red, purple, white, or gray
• Burning or stinging
• Blisters
• Dry, scaly skin on the soles of the feet that may extend up the side

Toenail fungal infection

Toenail fungus, also called onychomycosis, is any kind of fungal infection that occurs on or under the toenail. Usually starting out as a small white or yellow spot under the tip of the nail, the infection may eventually spread deeper into the nail and potentially lead to the loss of the toenail. Nail fungus can also affect the fingernails, although the infections occur more often in the toenails because shoes and socks create a damp environment. People with diabetes or certain other medical conditions should be extra cautious of contracting fungal infections of the toenail, as it can lead to serious complications.

There are three main types of toenail fungus:

• subungual onychomycosis
• white superficial onychomycosis
• candida onychomycosis

Eumycetoma (fungal mycetoma) 

Eumycetoma, also known as Madura foot, is a persistent severe infection most commonly affecting the skin and the tissues of the feet, although it can occur in the hands and other areas of the body. Eumycetoma is a skin disease that primarily affects those in tropical and subtropical climates who are in direct contact with the soil. A healthcare professional can diagnose eumycetoma by taking a biopsy and inspecting the fungi under a microscope. 

Several fungi can cause eumycetoma:

• Madurella mycetomatis
• Madurella grisea
• Leptosphaeria senegalensis
• Curvularia lunata
• Scedosporium apiospermum
• Neotestudina rosati
• Acremonium and fusarium species

Foot fungus symptoms

Athlete’s foot (tinea pedis)

Fungal infections of the feet normally start in between the toes of the foot, commonly between the fourth and fifth toe. The infection may spread to the sides of the foot, the sole, and the heel of the foot. The signs and symptoms of athlete’s foot include:

• Scaling, peeling or cracked skin between the toes
• Itching
• Inflamed skin that appears red, purple, white, or gray
• Burning or stinging
• Blisters

Toenail fungal infection

Fungal infections may affect a single toenail or multiple toenails, commonly infecting the big toe first. It may also affect the surrounding skin. The most common symptoms of toenail fungal infections include: 

• Whitish or yellowish discoloration of one or more toenails
• Brittle, crumbly, or thickened nail 
• Part of the nail may lift from the nail bed or the entire nail may fall off
• Skin surrounding the nail may be red and inflamed
• Pain may occur along with a bad odor

Eumycetoma (fungal mycetoma) 

Eumycetoma starts as a painless, firm nodule or mass under the skin which may be present for years. If untreated, the affected tissue may swell and lead to open sores with a grainy discharge followed by adjacent bone deformity. Chronic, disabling pain may result as the infection progresses.

Foot fungus treatment

Athlete’s foot (tinea pedis)

There are a number of effective treatment options for athlete’s foot. Non-medical treatments include measures such as keeping feet clean and dry and wearing light, well-ventilated footwear. Over-the-counter (OTC) antifungal treatments such as Lamisil AT (terbinafine), Tinactin (tolnaftate), Zeasorb AF (miconazole), and Lotrimin AF (clotrimazole) have been shown to be very effective. These products are available in a variety of formulations such as ointments, gels, creams, lotions, powders, and sprays. By applying the product to the infected area as directed (typically twice daily), it usually takes two to four weeks to see results. 

If OTC treatments have not been effective, a healthcare professional may recommend prescription antifungals, such as Ecoza (econazole) or Loprox (ciclopirox). If prescription topical treatments prove to be ineffective, the healthcare professional may then prescribe an oral antifungal medication, such as terbinafine or Diflucan (fluconazole). The dose and length of the oral treatments will depend on the severity of the infection.

Although an athlete’s foot condition can usually be treated effectively with improved hygiene and use of OTC products, one should consult a healthcare professional if the condition persists or if there are any color or texture changes to the skin or intense itchiness.

Toenail fungal infection

The goal of treatment of fungal toenail infections is to eliminate the fungus and restore the nail to its normal appearance. For mild fungal infections, there are some commonly available home remedies for treating toenail fungus that can be tried before turning to the more traditional OTC and prescription medical treatments which include the OTC products Lotrimin AF (clotrimazole) and Lamisil AT (terbinafine) and prescription products Ecoza (econazole),  Loprox (ciclopirox), Jublia (efinaconazole), and Kerydin (tavaborole). Oral antifungal prescription treatments include terbinafine, Diflucan (fluconazole), Sporanox (itraconazole), and Noxafil (posaconazole). 

Antifungal medications prescribed by a healthcare provider may be necessary in more severe cases or when home remedies or OTC medications do not work. Topical antifungals are typically used before oral systemic treatments, particularly if drug interactions or an allergic reaction are a concern. A combination of topical and oral drug therapy may be recommended. After initiating treatment, it typically can take three to four months to see results. In rare cases of total nail involvement or treatment-resistant fungal infections, laser therapy may be an option or the toenail itself may need to be removed. 

Eumycetoma (fungal mycetoma) 

Eumycetoma is a serious condition that is a major health problem in equatorial regions of the world that are known for humid conditions. Fortunately, cases of eumycetoma are rarely reported in the United States. Eumycetoma is usually treated under the care of a doctor with patients on long periods of antifungal therapy. Various types of antifungals have been used in the treatment of eumycetoma, including Sporanox (itraconazole), Noxafil (posaconazole), and terbinafine. Because it is a persistent infection, drug treatment may not be completely effective and surgery is often necessary to cut away the infected tissue.

How to prevent foot fungus

With proper treatment, fungal infections of the foot are a manageable condition. Prevention of a fungal infection of the feet should always be the goal–these tips can help:

• Keep feet clean and dry
• Change socks regularly, particularly if you have sweaty feet, or wear socks that are sweat-wicking
• Wear light, well-ventilated footwear and, if possible, alternate pairs of shoes from day to day
• Wear sandals or flip-flops when possible to let your feet air out
• Wear waterproof sandals or shoes in damp environments such as gyms, public showers, locker rooms, and around public pools
• Don’t wear another person’s shoes
• Specific to preventing fungal nail infections:
  • Avoid trimming nails too short
  • Avoid unhygienic cosmetic nail practices