What is athlete's foot? Causes, treatment, and prevention

Athlete's foot, or tinea pedis , is one of the most common fungal infections in the world, affecting approximately 15% of the global population. Although its name may suggest that it only affects athletes, the reality is that it can develop in anyone who meets certain conditions, especially if frequently exposed to warm, humid environments.

This infection is mainly caused by dermatophyte fungi, especially of the genus Trichophyton (such as T. rubrum and T. mentagrophytes ) that feed on the keratin present in the skin.

Fungi tend to thrive in warm, dark, and moist environments, such as the inside of athletic shoes or public showers, making them a common problem among people who wear closed-toe shoes for long hours or whose feet sweat excessively.

The infection usually begins between the toes and, although it may seem harmless, requires proper attention and treatment to avoid serious complications.

Symptoms of athlete's foot

Symptoms of athlete's foot can vary depending on the type of infection, but common signs and symptoms include:

• Peeling and cracked skin, especially between the toes (especially between the fourth and fifth).
• Intense itching, often accompanied by burning, especially just after removing shoes and socks.
• Redness or inflammation of the skin.
• In some cases, blisters or lesions may ooze.
• Bad smell associated with infection.

If you're going to be playing sports or spending long hours with your feet in closed, poorly ventilated footwear, such as boots, wear technical socks that breathe well.

If not treated promptly, the infection can spread to the sole of the foot (moccasin-like) or even to the nails, causing onychomycosis.

Main types of athlete's foot

Athlete's foot can manifest in different ways depending on its location and clinical characteristics:

1. Interdigital type: This is the most characteristic form, with redness, maceration (softening of the skin due to moisture), fissures and peeling, most frequently observed between the fourth and fifth toes.

2. Hyperkeratotic or "moccasin" type: Typically presents with irregular or diffuse scaling on the lower, medial, and lateral parts of the feet, resembling the shape of a moccasin.

3. Vesicular/inflammatory type: Characterized by painful, pruritic (itchy or burning) vesicles or blisters, most frequently on the instep or anterior plantar surface.

Causes and risk factors

Athlete's foot is caused by the same type of fungus (dermatophytes) that causes ringworm. Damp socks and shoes, warm conditions, and humidity can encourage the growth of these organisms.

Main risk factors:

• Occlusive footwear: Wearing closed shoes frequently.
• Excessive sweating: Sweating intensely.
• Exposure in public places: Walking barefoot in public areas where infection can spread, such as locker rooms, saunas, swimming pools, communal bathrooms and showers.
• Direct contact: Sharing carpets, rugs, bedding, socks, or shoes with someone who has a fungal infection.
• Medical conditions: Diabetes, immunosuppression or circulatory problems.

The tropical climate is more humid and causes excessive sweating, which is aggravated by occlusive clothing, socks and footwear, predisposing to dermatophyte infections.

Transmission and contagion

Athlete's foot is contagious and can be spread through contact with an infected person or contaminated surfaces, such as towels, floors, and shoes. You can also spread it from your foot to other parts of your body, especially if you scratch or touch infected areas of your foot.

According to a study published in the Journal of the American Academy of Dermatology, 25-30% of untreated cases progress to a chronic form.

Patients contract the infection through direct contact with the organism while walking barefoot. The fungi can survive on moist surfaces for extended periods, making community facilities such as swimming pools and showers important sources of transmission.

Treatment of athlete's foot

Treatment is usually effective if acted upon promptly. For most cases, topical treatment is recommended, using over-the-counter antifungal creams such as clotrimazole, terbinafine, or miconazole; typically for 1 to 4 weeks, depending on the product.

For more serious infections, prescription oral antifungals are required. They are typically prescribed for nail involvement or severe infections.

Public places, such as swimming pools or gym locker rooms, are very prone to fungal infections.

In all cases, it is essential to maintain strict foot hygiene: wash and dry your feet well (especially between the toes, even using a hairdryer if necessary), change socks daily (or more than once a day), and wear footwear that offers adequate ventilation.

It is essential not to discontinue treatment prematurely, even if symptoms improve, as this can lead to relapse or resistance.

What are the consequences of not treating it?

Failure to treat athlete's foot in time can lead to significant complications:

• Secondary and more severe bacterial infections, such as cellulitis.
• Spread of the fungus to other parts of the body or to other people.
• Chronic or severe tinea pedis can result in lymphangitis, characterized by the appearance of red lines extending from the affected area and swelling and tenderness of the lymphatic vessels.
• Onychomycosis (fungal nail infection), which requires a much longer treatment.
• Frequent and persistent recurrences, with possible resistance to treatment.

According to a study published in the Journal of the American Academy of Dermatology, 25-30% of untreated cases progress to a chronic form.

Populations at special risk

Diabetic patients with tinea pedis are at increased risk of developing onychomycosis. Furthermore, the presence of interdigital tinea pedis is a risk factor for cellulitis in patients with lymphedema.

How to prevent athlete's foot

There are some simple habits that can make the difference between keeping your feet free of fungal infections or developing athlete's foot.

Personal hygiene

The main tip for preventing athlete's foot is to maintain proper hygiene. Wash your feet daily. Use warm, soapy water and rinse and dry your feet thoroughly, especially between the toes.

Change your socks regularly, at least once a day, and more often if your feet sweat a lot. If you're going to be exercising or spending long periods of time with your feet in closed, poorly ventilated footwear, such as boots, wear highly breathable technical socks , such as Podoks, which are designed to keep your skin dry and friction-free thanks to their Coolmax fabric.

Shoe care

If you've had an infection before, disinfect your shoes. It's also advisable to rotate sneakers or shoes and not wear the same ones every day. This way, your shoes will have time to dry after each use.

Let your feet air out. Whenever possible, wear sandals to allow your feet to air out as much as possible.

Precautions in public places

Public places, such as swimming pools or gym locker rooms, are particularly prone to fungal infections. Avoid sharing towels and, above all, avoid going barefoot in public showers, gyms, or pools. Wear sandals or waterproof shoes (the famous flip-flops) when walking around pools, public showers, and shared locker rooms.

Conclusion

Athlete's foot is a common but treatable infection that requires proper care to prevent complications. These remedies generally cure the infection, but it can recur, so ongoing prevention is essential.

The key is to keep feet clean and dry, wear appropriate footwear, and seek medical treatment when necessary. It has been estimated that more than US$500 million per year is spent worldwide on medications to treat dermatophytosis, underscoring the importance of prevention as the most cost-effective strategy.

At Podoks , we design our socks with fabrics that promote foot breathability and have an antibacterial treatment to prevent infections.

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Scientific references:

Host-Pathogen Interaction and Resistance Mechanisms in Dermatophytes - MDPI Pathogens

Dermatophytic Diseases: A Review of Tinea Pedis - medRxiv

Tinea Pedis - StatPearls - NCBI Bookshelf

Dermatophyte Infections Worldwide: Increase in Incidence and Associated Antifungal Resistance - MDPI Life

Review on host-pathogen interaction in dermatophyte infections - ScienceDirect

A Foot in the Door for Dermatophyte Research - PLOS Pathogens

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

Elewski BE. Tinea pedis: diagnosis and treatment. J Am Acad Dermatol. 1994;31(3 Pt 2):S31-33. doi:10.1016/0190-9622(94)90264-x

MedlinePlus. Athlete's foot (tinea pedis). https://medlineplus.gov/spanish/athletesfoot.html