Athletes Foot

In this article:

• What Is Athlete’s Foot (tinea pedis)?
• Is Athlete’s Foot Contagious?
• How Long Does Athlete’s Foot Last?
• Signs & Symptoms of Athlete’s Foot
• When to see a doctor
• What Causes Athlete’s Foot?
• Who is at risk for athlete’s foot?
• References

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What Is Athlete’s Foot (tinea pedis)?

Athlete’s Foot (Tinea Pedis) is a common fungal infection that occurs on the foot. Tinea infections are caused by dermatophytes and are classified by the involved skin location. It is also known as a foot rot. The most common infections in prepubertal children are tinea corporis and tinea capitis, whereas adolescents and adults are more likely to develop tinea cruris, tinea pedis, and tinea unguium (onychomycosis). 

The symptoms can be confusing, as some other diseases and conditions can present very similar. For example, allergic reactions and contact dermatitis may look identical.

 Approximately 15-25% of people will be affected at some point in their lifetime. Typically, Athlete’s Foot affects the soles of the feet, in between the toes, and/or in the toenails. Usually, it only infects hairless skin. 

The most common causative fungus is Trichophyton rubrum; it is responsible for 70% of cases. The fungus causes discoloration, skin changes, and itchiness to the affected area. The fungus is a dermatophyte fungus that is part of the phylum Ascomycota. 

Is Athlete’s Foot Contagious?

Yes, it can spread when there is direct contact to others or when there is direct contact to other parts of your body. Make sure to wash your hands if you touch the affected area. It favors warm humid climates and can spread from touching an infected towel, shoes, or contaminated floors. You will not become infected by standing next to someone that has Athlete’s Foot. There must be direct contact with your skin and the organism.

How Long Does Athlete’s Foot Last?

Without treatment, Athlete’s Foot can last indefinitely. It usually requires treatment to cure the infection since this fungus does not cause your body to elicit a strong inflammatory response when it invades the skin. With treatment, your skin should start to return to normal in 1-4 weeks.

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Signs & Symptoms of Athlete’s Foot

The most common symptoms of the athlete’s foot are:

• Itching and burning of the foot soles and toes
• Cracking and peeling of the foot soles
• Discoloration of the foot’ skin on the heels and sides
• Unpleasant smell when the feet are wet

Athlete’s foot invades the top layer of the skin (the epidermis) and causes discoloration and cracked skin. In the early stages you might just feel an uncomfortable feeling between the toes. It may appear to be an area of blisters. Depending on your skin color, the area will often appear pink or white with red or silver scaly skin. It is frequently itchy (especially after removing your socks and shoes.) 

Occasionally there will be a burning sensation and bleeding from cracked skin. There are usually no systemic effects (full body effects) such as fever, fatigue, or chills. 

When to see a doctor

Generally, Athlete’s Foot can be resolved with over-the-counter antifungal medications from your local pharmacy. The medication is topical (which means it is applied directly to the skin) and will usually resolve in 1-4 weeks. However, if your symptoms do not resolve after completing this treatment or if blisters are present, your doctor may need to prescribe an oral antifungal. These require a prescription. 

If you start to develop symptoms of fever, muscle aches, or chills, go see your doctor. These may be signs that the infection has spread to other parts of your body. This is especially important if you are diabetic or have a weakened immune system. 

It is important to see a dermatologist if none of the OTC creams worked. It can be that you are mistaken in your diagnosis. Here are some diseases that mimic athlete’s foot:

1. Contact dermatitis. Distribution may match footwear; usually spares interdigital skin
2. Dyshidrotic eczema. “Tapioca pudding” vesicles on lateral aspects of digits; often involves hands
3. Foot eczema. May have atopic history; usually spares interdigital skin
4. Juvenile plantar dermatosis. Shiny taut skin involving great toe, ball of foot, and heel; usually spares interdigital skin
5. Psoriasis. Involvement of other sites; gray or silver scale; nail pitting; 70% of affected children have family history of psoriasis

Interdigital erosions are frequently due to tinea pedis. However, other infectious conditions, such as candidiasis, erythrasma or bacterial infections, can generate lesions that cannot be differentiated at the clinical level. Microbiological tests are therefore necessary.

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What Causes Athlete’s Foot?

The organism that causes Athlete’s Foot is a fungus that thrives in warm, moist, and humid environments. It is frequently found in community baths, showers, and pools. The fungus releases enzymes that help it break down the outermost layers of your skin so that it can attach and continue to grow. While there are multiple different fungi than cause Athlete’s Foot, the majority of cases (70%) are caused by Trichophyton rubrum. 

When feet are healthy, the fungus never invades. It likes the conditions created by uncomfortable and unbreathable footwear, or when someone does not take the shoes for a prolonged period of time. In such situations the skin cannot maintain the integrity between layers – they separate allowing fungal cells to get inside the skin. If it happens just one time, the immune system usually gets rid of the fungal cells, but once the trichophyton starts growing it is really hard to get rid of it.

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Who is at risk for athlete’s foot?

You are at an increased risk if the following apply to you: 

• Live in a hot and humid environment
• Wear occlusive footwear (especially if moist) for long periods of time
• Walk barefoot around community baths, showers, and pool areas 
• Sweat excessively 
• Sharing socks or shoes with an infected person

You can help avoid contracting Athlete’s Foot by wearing shoes when walking in communal showers or pool areas. Bringing a fresh pair of socks or alternating your shoes during hot and humid months can also help. 

The relation between tinea pedis and the internal environment of footwear has now been evaluated by scientists and published in the Journal of Dermatology in 2019. This study aimed to determine whether the internal environment of footwear affects the incidence of tinea pedis and tinea unguium. This cross-sectional, observatory study involved 420 outpatients who were categorized into non-tinea, tinea pedis or tinea unguium groups based on mycological analysis. 

External climatic conditions, and temperature, humidity and dew points inside the patients’ footwear were recorded. Univariate and multivariate analyses were used to determine independent risk factors for tinea pedis and tinea unguium. A significant correlation was found between high temperature/high humidity and dew point of the internal environment of the footwear and the season. 

Furthermore, those who wore footwear with internal environments characterized by high temperature, high humidity, high-temperature/high-humidity and high dew point values had a significantly higher incidence of tinea pedis. The internal dew point correlated with the incidence of tinea pedis, whereas the external temperature correlated with the incidence of tinea unguium. 

The internal humidity and dew point of footwear as well as the frequency with which footwear with a high-temperature/high-humidity internal environment were worn was significantly higher in men than in women. In conclusion, the internal environment of footwear is a risk factor for tinea pedis, and this environment is affected by the season. Moreover, the frequency of tinea pedis among men is related to the internal environment of footwear. The dew point is an appropriate index for evaluating temperature and humidity in relation to tinea pedis.

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References:  

Internal environment of footwear is a risk factor for tinea pedis. Sasagawa Y.J Dermatol. 2019 Nov;46(11):940-946. doi: 10.1111/1346-8138.15060. Epub 2019 Aug 22.PMID: 31436337 Free PMC article.

Tinea Pedis. Nigam PK, Saleh D.2021 Jun 7. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan.

Athlete’s foot.Crawford F.BMJ Clin Evid. 2009 Jul 20;2009:1712.

Diagnosis and management of tinea infections. Ely JW, Rosenfeld S, Seabury Stone M.Am Fam Physician. 2014 Nov 15;90(10):702-10.