Athlete's foot: causes, treatment, and prevention guide

Athlete's foot, medically known as tinea pedis, is one of the most widespread fungal infections in the United States, affecting an estimated 15% to 25% of people at any given time. Despite its name you don't need to be an athlete to develop it. Anyone who creates the right conditions for fungal growth can fall victim to this uncomfortable infection.

Athlete's foot is caused by dermatophytes, including Trichophyton rubrum, T. mentagrophytes, T. interdigitale, and Epidermophyton floccosum. These microscopic fungi thrive in warm, moist environments and feed on keratin, the protein found in your skin, hair, and nails.

T. rubrum accounts for approximately 70% of tinea pedis cases, making it the primary culprit behind most athlete's foot infections. What makes this fungus particularly problematic is its ability to survive and spread easily in communal areas like locker rooms, pools, and shower facilities.

The infection typically begins between the toes, particularly between the fourth and fifth toes, and can spread to other areas of the foot if left untreated. While it may seem like a minor inconvenience, athlete's foot requires proper attention and treatment to prevent complications and ensure complete recovery.

What causes athlete's foot?

Understanding the root causes of athlete's foot is essential for both treatment and prevention. The condition is typically acquired by coming into contact with infected skin, or fungus in the environment.

The fungal culprits

Dermatophytes are classified into three genera: Trichophyton, Microsporum, and Epidermophyton. These fungi have evolved specifically to infect the outer layers of human skin, making them particularly well-adapted parasites.

Fungal spores from T. rubrum can live in human scales for 12 months and are therefore easily transmitted from person to person in locker rooms and public showers. This remarkable survival ability explains why athlete's foot can be so persistent and why reinfection is common.

How the infection spreads

The disease may spread to others directly when they touch the infection. People can contract the disease indirectly by coming into contact with contaminated items (clothes, towels, etc.) or surfaces (such as bathroom, shower, or locker room floors).

The fungus particularly thrives in environments that are:

• Warm and humid.
• Dark and poorly ventilated.
• Frequently exposed to moisture.
• Shared by multiple people.
  

Risk factors and who's most vulnerable

While anyone can develop athlete's foot, certain factors significantly increase your risk:

Demographics and health conditions

Men and older people are more likely to get it. Adult males have a higher prevalence of tinea pedis than females. Additionally, independent risk factors for the development of tinea pedis included advanced age, male sex, diabetes, and lower-limb ischemia.

Lifestyle and environmental factors

Your daily habits and environment play crucial roles in determining your risk level:

• Occlusive footwear: Wearing occlusive shoes for extended periods predisposes patients to dermatophyte infections.
• Excessive sweating: Heavy foot perspiration creates the ideal breeding ground for fungi.
• Public facilities: Community facilities involving water are likely to increase the chances of infection, as tinea pedis rates are higher among those who use community baths, showers
• Poor foot hygiene: Inadequate cleaning and drying of feet.
• Compromised immune system: Conditions that weaken immunity increase susceptibility.
  

Recognizing the symptoms

Athlete's foot can manifest in several ways, and recognizing the symptoms early is crucial for prompt treatment. Athlete's foot occurs most often between the toes (interdigital), with the space between the fourth and fifth digits (the little toe and the fore toe) most commonly affected.

Common signs and symptoms

The most frequent symptoms include:

• Itching and burning: Often most intense right after removing shoes and socks.
• Scaling and peeling: Particularly between the toes.
• Redness and inflammation: Affected areas may appear irritated.
• Cracking and fissuring: The skin may develop painful splits.
• Odor: A distinctive smell often accompanies the infection.
• Blisters: In some cases, fluid-filled lesions may develop.

Types of athlete's foot

Athlete's foot can be categorized into four main types: interdigital (toe webs), moccasin, vesicular (blisters), and ulcerative.

Interdigital type: The most common form, affecting the spaces between toes. Cases of interdigital athlete's foot caused by Trichophyton rubrum may be symptomless, it may itch, or the skin between the toes may appear red or ulcerative (scaly, flaky, or soft and white if skin has been kept wet).

Moccasin type: Plantar athlete's foot (moccasin foot) is also caused by T. rubrum which typically causes asymptomatic, slightly erythematous plaques (areas of redness of the skin) to form on the plantar surface (sole) of the foot.

Vesicular type: Characterized by painful blisters and fluid-filled lesions, typically appearing on the arch or sole of the foot.

Ulcerative type: In ulcerative-type infections, the interdigital infection spreads to the dorsum (top) or plantar surface of the foot. They have characteristics similar to those of macerated infections and are usually secondarily infected with bacteria.

Effective treatment options

The good news is that athlete's foot is highly treatable when addressed properly. Although athlete's foot doesn't cause any serious problems in people who are otherwise healthy, it normally doesn't go away on its own.

Over-the-counter treatments

Topical (external) treatment such as creams or gels can usually successfully get rid of the infection. It is very rarely necessary to take tablets.

First-Line Topical Antifungals:

Terbinafine (Lamisil): The most effective of all OTC treatments, according to the American Academy of Family Physicians, terbinafine is an antifungal product that kills the fungus and keeps it from coming back by inhibiting an enzyme it requires to grow. Applying Lamisil cream once a day for one week heals up to 97% of all cases.

Clotrimazole (Lotrimin): Clotrimazole is an enzyme-inhibiting product that gets rid of fungus and prevents it from growing back.

Miconazole (Micatin): Miconazole halts and prevents fungal growth by inhibiting an enzyme.

Tolnaftate (Tinactin): Tolnaftate inhibits an enzyme to stop the growth of fungus and prevent its recurrence.

Treatment duration and compliance

When recommending nonprescription products, pharmacists should stress the importance of adhering to the regimen, applying the substance as often as directed, and completing the full course of therapy as suggested on the label.

For example, studies on the effectiveness of allylamine products showed that, after six weeks, athlete's foot had cleared up in 17 out of 100 people who didn't treat it, and in 73 out of 100 people who used the medication.

When to seek prescription treatment

Tablets are only considered if topical treatment isn't successful. It may also be a good idea if the infection has spread to one or more toenails, or if the infection is very severe.

Oral antifungal options:

Terbinafine: Terbinafine is typically taken once daily for two weeks (dose: 250 mg).

Itraconazole: Itraconazole is usually taken once daily for four weeks (dose: 100 mg).

Oral terbinafine may be more effective than griseofulvin at improving mycological cure at 4 to 8 weeks in adults with athlete's foot.

Potential complications of untreated athlete's foot

Ignoring athlete's foot can lead to serious complications that are much more difficult to treat than the original infection.

Secondary bacterial infections

When the skin barrier is compromised by fungal infection, bacteria can enter through cracks and fissures, leading to cellulitis, a potentially serious bacterial skin infection that may require hospitalization.

Spread to other body parts

If left untreated, it can spread to a nail and cause a fungal nail infection. Patients with diabetes with tinea pedis are at a higher risk of developing onychomycosis. Furthermore, the presence of interdigital tinea pedis is a risk factor for cellulitis in patients with lymphoedema.

Chronic and recurrent infections

Untreated athlete's foot often becomes chronic, making it increasingly resistant to treatment and more likely to recur even after successful therapy.

Prevention: your best defense

It has been estimated that over US$500 million per year is spent worldwide on drugs to treat dermatophytoses, highlighting the importance of prevention as the most cost-effective strategy.

Essential Foot Hygiene Practices

Daily Care Routine:

• Wash feet thoroughly with soap and warm water.
• Dry completely, especially between toes.
• Change socks daily, or more frequently if you sweat heavily.
• Alternate shoes to allow 24 hours of drying time between uses.

Smart footwear choices

Sock Selection: Choose moisture-wicking materials over cotton. Technical socks with antimicrobial properties, like those designed by Podoks, help maintain dry conditions and reduce bacterial growth that can complicate fungal infections.

Shoe Materials: Warm, moist environments are ideal conditions for athlete's foot. Tight, nonbreathable, or restrictive footwear causes excessive friction and sweating, which encourage fungal growth. Opt for breathable materials and proper fit.

Public area precautions

Frequent changing of socks, the application of powder to absorb moisture, and the wearing of sandals in locker rooms and public showers are key for preventing infection.

Never walk barefoot in:

• Public showers and locker rooms.
• Swimming pool areas.
• Gym facilities.
• Hotel bathrooms.

Regularly hosing the floors of shower rooms and the sides of swimming pools decreases the presence of dermatophytes on these surfaces.

Additional preventive measures

• Use antifungal powder in shoes if you have a history of athlete's foot.
• Avoid sharing towels, socks, or shoes.
• Keep toenails short and clean.
• Address any foot injuries promptly to prevent secondary infections.
  

When to see a healthcare provider

While most cases of athlete's foot respond well to over-the-counter treatments, certain situations require professional medical attention:

• Symptoms persist after 2-3 weeks of proper treatment.
• Signs of bacterial infection (increased redness, warmth, pus, red streaking).
• If you have diabetes or compromised circulation.
• Severe blistering or ulceration.
• Fever accompanying foot symptoms.
• Spreading to toenails or other body parts.

The role of quality socks in prevention

At Podoks, we understand that prevention is always better than treatment. Our biomechanical socks are designed with moisture-wicking Coolmax fabric and antimicrobial treatment to create an environment that's hostile to fungal growth while supporting optimal foot health.

The right socks can make a significant difference in maintaining the dry conditions that prevent fungal infections from taking hold. By investing in quality moisture-management technology, you're taking a proactive step toward long-term foot health.

Conclusion

Athlete's foot is a common but entirely preventable and treatable condition. The key to success lies in understanding the causes, recognizing symptoms early, following through with complete treatment courses, and most importantly, maintaining consistent preventive practices.

Since athlete's foot is a fungus, you need to treat it with an antifungal medication, and with the wide array of effective over-the-counter options available, most people can successfully manage this condition at home.

Remember that prevention is your most powerful tool. By keeping your feet clean and dry, choosing appropriate footwear, and using quality moisture-wicking socks, you can significantly reduce your risk of developing athlete's foot and enjoy healthier, more comfortable feet.

Don't let athlete's foot sideline your active lifestyle. With the right knowledge and preventive measures, you can keep your feet healthy and infection-free.

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Scientific References:

Bell-Syer SE, Khan SM, Torgerson DJ. Oral treatments for fungal infections of the skin of the foot. Cochrane Database Syst Rev. 2012; 10: CD003584.

Gupta AK, Daigle D, Paquet M, et al. Topical treatments for athlete's foot. Cochrane Database Syst Rev. 2018;2018(1):CD010863.

Leung AK, Barankin B, Lam JM, Leong KF, Hon KL. Tinea pedis: an updated review. Drugs Context. 2023.

Mayo Clinic. Athlete's foot. https://www.mayoclinic.org/diseases-conditions/athletes-foot

National Institute for Health and Care Excellence. Athlete's foot - InformedHealth.org - NCBI Bookshelf

Tinea Pedis - StatPearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK470421/

Zeichner JA, Stein Gold L, Korotzer A. Penetration of topical antifungal agents into the hair follicle: considerations for the treatment of tinea capitis. J Am Acad Dermatol. 2018;78(1):74-79.