Athlete’s Foot – Causes, Symptoms, Treatments

What is Athlete’s Foot?

Athlete’s foot, also known as tinea pedis, is a common fungal infection that affects the skin on the feet. It is caused by a variety of fungi that thrive in warm, moist environments. Athlete’s foot is contagious and can spread from person to person through direct contact or contact with contaminated surfaces.

Common Causes of Athlete’s Foot

As previously mentioned, Athlete’s foot is primarily caused by fungi, specifically dermatophytes. Dermatophytes are a group of fungi that thrive on keratin, a protein found on the outermost layer of our skin (stratum corneum), hair, and nails. They are responsible for causing a variety of infections collectively known as dermatophytosis or tinea.

There are three main genera of dermatophytes that cause infections in humans. Trichophyton is the most common genus, responsible for infections like tinea capitis (scalp ringworm), tinea corporis (ringworm on the body), and tinea cruris (jock itch). Microsporum often causes tinea capitis and can also be transmitted from animals to humans (zoonophilic). Epidermophyton is less common and typically causes tinea cruris and tinea pedis (athlete’s foot).

Dermatophytes are not naturally present on the human body. They can live in the soil (geophilic), on animals (zoophilic), or on shed human skin cells (anthropophilic). These fungi can spread through direct contact with infected skin or by touching surfaces contaminated with the fungi. They thrive in warm, moist environments such as locker rooms, swimming pools, saunas, and communal showers. Once the fungi come into contact with susceptible skin, they can easily penetrate and cause infection.

The fungi responsible for athlete’s foot, prefer warm and humid environments. Sweat and moisture accumulate in areas like the spaces between toes, providing an ideal breeding ground for fungal growth. When feet remain damp for prolonged periods, especially within tight-fitting shoes or socks, it creates conditions conducive to fungal proliferation.

Neglecting foot hygiene can contribute to the development of athlete’s foot. Failing to wash and thoroughly dry the feet, especially between the toes, allows fungi to thrive. Additionally, reusing socks without washing them or wearing damp footwear can perpetuate the cycle of infection.

Tight-fitting shoes or non-breathable synthetic materials trap moisture and restrict airflow, promoting fungal growth. Shoes that do not allow proper ventilation can lead to sweaty feet, increasing the risk of infection. Furthermore, wearing shoes or sandals in public places like locker rooms or communal showers can increase exposure to fungi.

Individuals with compromised immune systems, such as those with diabetes, HIV/AIDS, or undergoing immunosuppressive therapy, are more susceptible to fungal infections like athlete’s foot. A weakened immune response makes it easier for fungi to invade and colonize the skin, leading to persistent or severe infections.

Direct contact with infected individuals or contaminated surfaces can transmit the fungi responsible for athlete’s foot. Sharing towels, socks, shoes, or walking barefoot in public areas where the fungi thrive increases the likelihood of acquiring the infection.

Certain pre-existing skin conditions, such as eczema or psoriasis, compromise the skin’s integrity and protective barrier. Cracks, fissures, or abrasions in the skin provide entry points for fungal pathogens, facilitating the development of athlete’s foot.

Some individuals may have a genetic predisposition to fungal infections, including athlete’s foot. Genetic factors influencing skin composition, immune response, or susceptibility to certain pathogens may contribute to an increased risk of infection.

Symptoms of Athlete’s Foot

Athlete’s foot, while a common nuisance, can cause a range of uncomfortable symptoms that vary in intensity and location. 

Itching, Burning, Stinging:

• This is often the most bothersome symptom, ranging from mild annoyance to intense irritation that disrupts daily activities.
• Itching is typically most pronounced between the toes, particularly in the web spaces (areas between toes).
• Burning or stinging can occur alongside itching or independently, affecting the soles, sides, or tops of the feet.

Skin Changes:

• Scaling: The skin may appear dry and flaky, with fine white or grayish scales developing.
• Cracking: Deeper cracks can form in the affected areas, sometimes causing pain or bleeding. These cracks are most common between the toes, especially the fourth and fifth toes.
• Peeling: The scaly skin might peel off in small or large patches, leaving the underlying skin raw and sensitive.

Inflammation:

• The affected area may become red and inflamed, often accompanied by a mild increase in warmth to the touch.
• This inflammation can contribute to the itching and discomfort.

Blisters:

• Small, clear, fluid-filled blisters may appear on the soles or sides of the feet.
• These blisters can be itchy and uncomfortable, and they may eventually break open and ooze.

Toenail Changes:

• In some cases, athlete’s foot can spread to the toenails, causing a fungal nail infection.
• Symptoms include:
  • Discoloration: Toenails may become white, yellow, brown, or black.
  • Thickening: The nails can become thicker and lose their normal shape.
  • Crumbling: The affected nails may become brittle and crumble easily.
  • Separation from the nail bed: In severe cases, the toenail may detach from the skin underneath.

Additional Symptoms:

• A strong, unpleasant odor emanating from the feet can be present, especially if the infection is severe or involves sweating.
• In rare instances, a secondary bacterial infection can develop on top of the fungal infection. This can cause additional symptoms like increased pain, swelling, redness, pus drainage, and fever.

Preventing Infection

Up to seventy percent of the population will contract athlete’s foot at some point in their lives. Although athlete’s foot is common, you can reduce your risk of athlete’s foot by following these suggestions:

Promote Dryness and Ventilation:

• Wash your feet thoroughly: Make foot hygiene a priority. Wash your feet daily with soap and warm water, paying particular attention to the areas between your toes. Ensure complete drying afterwards, especially between the toes. You can gently pat them dry with a clean towel or use a blow dryer on a cool setting.
• Wear breathable shoes and socks: Choose shoes made from natural, breathable materials like leather or canvas. Avoid tight-fitting shoes and opt for well-ventilated styles whenever possible. Likewise, select socks made from moisture-wicking materials like cotton or wool. Change your socks daily, especially if your feet tend to sweat a lot.
• Alternate shoes: Don’t wear the same pair of shoes every day. Allow them to air out completely for 24 hours between wearings. This helps eliminate moisture buildup that can harbor fungus.

Minimize Exposure:

• Avoid walking barefoot in public places: Fungus thrives in damp environments. Wear sandals or shower shoes in locker rooms, gyms, public pools, and showers.
• Don’t share personal items: Sharing towels, socks, or shoes with someone who has contracted athlete’s foot can easily spread the infection.
• Maintain dry surfaces: Keep your shower and bathroom floors clean and dry. Avoid letting water accumulate around bathtubs or showers.

Additional Tips:

• Keep your feet healthy: Regularly trim your toenails straight across to prevent ingrown nails, which can create entry points for fungus.
• Manage sweat: If you sweat heavily, consider using an antiperspirant foot spray or powder to help keep your feet dry.
• Strengthen your immune system: Maintaining a healthy immune system can help your body fight off fungal infections. Eat a balanced diet, get enough sleep, and manage stress levels.

How is Athlete’s Foot Diagnosed

In most cases, diagnosing athlete’s foot is a straightforward process for a doctor or dermatologist. Often, a simple visual examination of your feet is enough for diagnosis. The doctor will look for characteristic signs like scaling, cracking, peeling, redness, or blisters between the toes or on the soles of your feet.

The KOH Exam (Potassium Hydroxide Exam) is a quick and painless in-office test often used to confirm the presence of fungus. The doctor scrapes a small sample of skin from the affected area using a sterile scalpel or blade.

The sample is then mixed with a solution of potassium hydroxide (KOH) which dissolves human skin cells but leaves fungal cells intact. The doctor examines the sample under a microscope to identify fungal structures like hyphae (thread-like filaments) and spores. KOH exams are relatively inexpensive and provide results within minutes.

In some cases, if the KOH exam is inconclusive or another condition is suspected, a fungal culture might be ordered. During this test, a skin scraping is collected similar to the KOH exam but sent to a laboratory. The sample is placed on a special culture medium that promotes fungal growth. It can take several weeks for the fungus to grow, and then the lab identifies the specific type of fungus involved.

In very rare instances, a skin biopsy might be necessary. This involves taking a small sample of tissue from the affected area for examination under a microscope. A biopsy is usually only considered if other tests are inconclusive or there’s a concern about a different skin condition.

In most uncomplicated cases, the doctor can diagnose athlete’s foot based on the characteristic symptoms and visual examination. KOH exams provide additional confirmation and help rule out other potential causes of similar symptoms.

How is Athlete’s Foot Treated?

Athlete’s foot is usually treated with over-the-counter (OTC) antifungal medications. These medications come in various forms like creams, ointments, gels, sprays, and powders. Here’s a breakdown of the treatment approach:

Over-the-Counter Antifungal Medications:

• Types: Common OTC antifungal ingredients include clotrimazole, miconazole, terbinafine, and tolnaftate.
• Application: Apply the chosen medication according to the package instructions, typically once or twice daily for at least one to two weeks after symptoms clear. Consistent application is crucial for successful treatment.
• Benefits: OTC antifungals are readily available without a prescription, affordable, and effective for most cases of athlete’s foot.

Prescription Antifungal Medications:

• Scenario: In some cases, OTC medications might not be effective. This could be due to factors like a severe infection, involvement of the toenails, or a weakened immune system.
• Types: If OTC options fail, your doctor might prescribe stronger topical antifungal medications or oral antifungal pills. Oral medications like fluconazole, itraconazole, or terbinafine are typically reserved for more stubborn infections.
• Benefits: Prescription medications offer a more potent approach for tackling complicated or resistant cases.

Home Care Practices:

• Alongside medication, following good hygiene practices is essential for recovery and preventing recurrence.

Additional Tips:

• Antifungal powders: In some cases, your doctor might recommend using an antifungal powder to absorb moisture and create a less favorable environment for fungus growth.
• Steroid creams: If itching is severe, your doctor might prescribe a mild steroid cream to be used for a short period alongside the antifungal medication to reduce inflammation and discomfort.

What Medications are Most Often Prescribed for the Treatment of Athlete’s Foot?

While most cases of athlete’s foot respond well to over-the-counter (OTC) medications, there are situations where a doctor might prescribe stronger options. 

Prescription Topical Antifungal Medications:

These are typically reserved for cases where OTC antifungals haven’t been effective or the infection is more severe. They offer a higher concentration of the antifungal ingredient compared to OTC options. Here are some common types:

• Ciclopirox (Loprox): This medication works by disrupting the fungus’s cell membrane, hindering its growth and reproduction.
• Naftifine (Naftin): Naftifine disrupts the fungus’s cell wall and membrane, leading to its death.
• Butenafine (Mentax): Similar to Naftifine, Butenafine disrupts the fungal cell membrane, killing the fungus.
• Sertaconazole (Ertaczo): This broad-spectrum antifungal medication works by interfering with the fungus’s cell wall and membrane function.

Prescription Oral Antifungal Medications:

These are typically used for severe or widespread infections, involvement of the toenails (onychomycosis), or in individuals with weakened immune systems. Oral antifungals work systematically throughout the body, reaching areas that topical medications might not. Here are some commonly prescribed ones:

• Fluconazole (Diflucan): This broad-spectrum antifungal medication disrupts fungal cell wall synthesis, leading to the fungus’s death. Fluconazole is usually taken for a shorter duration compared to other oral antifungals.
• Itraconazole (Sporanox): Itraconazole works similarly to Fluconazole by disrupting fungal cell wall synthesis. It typically requires a longer treatment course than Fluconazole.
• Terbinafine (Lamisil): This medication disrupts fungal cell wall production and also inhibits an enzyme essential for fungal growth, leading to its demise. Terbinafine is generally well-tolerated and has a shorter treatment course compared to Itraconazole.