Athlete’s foot is a common foot infection caused by infection with certain types of fungi, called dermatophytes—these are the same fungi that cause ringworm and jock itch. Dermatophytes grow best in moist, damp places, which is why infection commonly spreads in the shower areas of gyms and swimming pools. Active people who wear tight, thick socks and heavy shoes are at increased risk of getting this infection, especially in hot weather. Athlete’s foot is more common in teens than in younger children.
What does it look like?
- The feet become itchy and tender, especially in the spaces between the toes. One or both feet may be affected.
- Peeling and cracking of the skin occur between and under the toes and on soles of the feet. Unpleasant foot odor may occur.
- Sometimes, especially in younger children, blisters and pustules (pimples) develop.
- If the infection is present for a long time, the bottom of the foot may become thickened and scaly.
How is Athlete’s foot transmitted?
- Direct contact with the infected area
- Indirect contact through contaminated surfaces such as gym change rooms and shower areas
- The infection can also be spread from one site on the body to other sites. Tinea pedis can spread to the groin (tinea cruris) or scalp (tinea capitis). Dermatophytes especially like to live in moist, warm areas of the body or on the scalp.
In ancient times, athlete’s foot was attributed to insect bites. (In medical Latin it’s called tinea pedis, or foot larvae.) However, in the 19th century a team of scientists discovered that microorganisms were responsible! Although a variety of fungi can cause foot rashes, Trichophyton mentagrophytes cause the itchy, cracked skin typically found between the fourth and fifth toes.
- Frequency: Tinea pedis is thought to be the world’s most common dermatophytosis. Reportedly, 70% of the population will be infected with tinea pedis at some time.
- Race: Tinea pedis has no predilection for any racial or ethnic group.
- Sex: Tinea pedis more commonly affects males compared with females.
- Age: The prevalence of tinea pedis increases with age. Most cases occur after puberty. Childhood tinea pedis is rare.
Athlete’s Foot Causes
Dermatitis affecting the foot can be caused by contact allergens, irritants, sweat and rash (intertrigo), poorly fitting shoes, psoriasis, and interdigital bacterial toe web infections, and fungal infections.
- Fungi (either yeasts or molds) cause athlete’s foot.
- Tinea pedis is most commonly caused by Trichophyton rubrum (60%), by Trichophyton mentagrophytes (20%), and by Epidermophyton floccosum (10%); more rarely by Microsporum canis, Trichophyton tonsurans and by other dermatophyte species, with differences by geographic area and by age of the patient.
- These fungi can be contracted by sharing the shoes or socks of an infected person.
- They need a warm moist environment to flourish and can be found growing on the floors of locker rooms and public showers and in swimming pools and whirlpools.
- Athlete’s foot seems to be relatively uncommon in humans who rarely wear closed shoes. It is most common is older adult
You are at higher risk of athlete’s foot if you:
- Are a man
- Frequently wear damp socks or tightfitting shoes
- Share mats, rugs, bed linens, clothes or shoes with someone who has a fungal infection
- Walk barefoot in public areas where the infection can spread, such as locker rooms, saunas, swimming pools, communal baths and showers
Symptoms associated with Athlete’s Foot
Athlete’s foot is a fungal infection which affects the outer layers of the skin and nails and which can occur in any age group. It may have some or all of the following symptoms:
- Red or raw looking skin, which is often itchy.
- Cracking, peeling or scaling of the skin between the toes.
- White and soggy skin, especially between the fourth and little toes.
- Sore, fluid filled, or weeping rash.
- Small spot like blisters on one or both feet.
- A dry scaly rash on the bottom and sides of the feet.
- Thickening of the affected nail.
- Discolouration – yellow or brown appearance.
- Deformity- oddly shaped nail which may separate from the skin at the free edge.
- Lack of growth.
- Discomfort or minor pain
- Your athlete’s foot infection can spread to other parts of your body, including:
- Your hand. People who scratch or pick at the infected parts of their feet may develop a similar infection in one of their hands.
- Your nails. The fungi associated with athlete’s foot can also infect your toenails, a location that tends to be more resistant to treatment.
- Your groin. Jock itch is often caused by the same fungus that results in athlete’s foot. It’s common for the infection to spread from the feet to the groin as the fungus can travel on your hands or on a towel.
Diagnosis and Test
- Is made most often by history and clinical presentation
- A skin lesion potassium hydroxide (KOH) exam is the most common test for athlete’s foot. A doctor scrapes off a small area of infected skin and places it in potassium hydroxide (KOH). The KOH destroys normal cells and leaves the fungal cells untouched so they are easy to see under a microscope.
- A fungal culture can be done also, though usually isn’t due to the length of time needed to get results.
- Chronic tinea pedis can look like eczema or psoriasis
How to treat Athlete’s foot?
The following over-the-counter creams can be used to provide symptom relief and treat Athlete’s foot. These creams need to be applied once up to twice or as directed by your health care provider daily on clean and dry feet for up to 4 weeks including 1 to 2 weeks after the lesion has disappeared to prevent it from recurring.
- Clotrimazole 1% (Canesten Athlete’s foot cream)
- Miconazole nitrate 2% (Micatin) – available as a cream, spray and powder
- Tolnaftate 1% (Tinactin Cream) – available as a cream, spray, gel and aerosol
The side effects of these creams are very mild and rare. Some possible side effects include local skin irritation including itching and redness.
Topical antifungal medications for athlete’s foot are widely available over-the-counter (OTC). Topical means medication that is applied directly to the area being treated. It is usually down to personal preference as to which form of antifungal medicine you use. Ask your pharmacist which antifungal medicine would be most suitable.
Types of antifungal medicine available include:
Different types of oral antifungal medicines are also available. These need to be prescribed by your GP and include:
Oral antifungal treatment is only recommended for severe cases of infection and if topical antifungal treatment has not worked. Oral medication is suitable for adults but not for children under 16 years of age.
- Wash your feet daily with soap and tepid water.
- Dry your feet thoroughly paying particular attention between the toes.
- Choose hosiery made from natural fibres which allows moisture to evaporate.
- Change your socks or hosiery daily.
- Do not share towels, socks or shoes.
- Wear well-fitting shoes or sandals, which allow the air to circulate.
- Choose shoes made from a natural fibre such as leather which allow the feet to breathe.
- Paint surgical spirits in between your toes daily with a cotton bud and allow to evaporate and dry.
- Do not use surgical spirits if it ‘stings’.
- If you are applying cream for your skin infection or treatment to the nails, it is important to treat all your shoes or slippers with an antifungal powder or spray and wash socks well, preferably a hot wash.
- A number of different organisms can cause fungal infection, which can appear in varying levels of severity on the skin and nails.
- Footwear creates an ideal environment for fungal growth by keeping feet warm and trapping moisture between the toes.
- This fact coupled with the use of communal facilities such as sports changing rooms, results in the effective spread of fungal infections.