Athlete's foot

Athlete's foot (tinea pedis) is particularly common between the little toe and the toe next to it. The fungus can cause the skin to redden and crack. The affected areas are flaky and sometimes itchy. The skin can also turn white and thicken, and is then often slightly swollen.

If the infection spreads across the sole of the foot it is referred to as moccasin athlete's foot. The soles of the feet, the heels and the edges of the feet are then dry, scaly and may be itchy. Moccasin athlete's foot is sometimes mistaken for other conditions such as eczema.

A rare kind of athlete's foot causes an acute inflammation associated with skin redness, blisters, pus-filled bumps and open sores. The skin may itch and feel tight.

Athlete's foot is usually caused by fungi that infect the skin (dermatophytes). They can enter the skin through small cracks or wounds, and infect the top layer.

The fungi are passed on through direct skin contact or through contact with flakes of skin. That can happen if, for instance, you step on infectious flakes of skin in communal showers. The same fungi can also cause fungal nail infections.

Fungal skin infections need moisture and warmth to spread. Our feet offer a perfect environment for them, because we wear shoes for most of the day and so our feet are often warm and moist. The skin on our feet also contains a lot of keratin, – a protein that can be found in the top layer of skin. The fungi feed on this.

Certain risk factors can increase the risk of athlete's foot. These are the main ones:

• A genetic predisposition (if a lot of people in your family have it),
• Allergies and eczema
• Particularly sweaty feet
• A weak immune system, for instance due to a serious illness or the long-term use of medication that weakens the immune system
• Circulation problems in the legs, for example as a result of diabetes or narrowed blood vessels
• Some sports, especially running and swimming

People who always have to wear sturdy shoes at work, such as safety boots or rubber boots, are also at higher risk.

Athlete's foot is very common. It is estimated that 3 to 15% of the population are affected. Men and older people are more likely to get it.

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. If left untreated, it can spread to a nail and cause a fungal nail infection. The infection can spread to other areas of skin, such as the hands, but that rarely happens.

Very rarely, and only in severe cases of athlete's foot, it can also lead to a bacterial infection.

The doctor examines the affected parts of skin and asks about the symptoms. They may take a skin sample to rule out other similar skin conditions. That involves scraping off a small amount of skin and treating it with a chemical agent to identify fungal spores under a microscope. The results are often available the next day. In rare cases, a fungal culture will be grown in a laboratory in order to determine the exact strain of fungus. That takes around three weeks.

Because fungi grow particularly well in a moist environment, it's important to make sure you keep your feet dry. You might try the following, for example:

• Thoroughly drying your feet with a towel after having a shower or bath, or after swimming
• Wearing shoes that aren't too tight and let your feet breathe
• Not wearing the same pair of shoes two days in a row
• Taking your shoes off as often as possible

The following things can help keep you from getting athlete's foot from infected flakes of skin and stop it from coming back:

• Wearing flip-flops when using swimming pools, communal showers and changing rooms
• Not sharing towels, shoes, or socks
• Washing socks, bedding and towels at 60 degrees Celsius or more
• Adding special anti-fungal laundry sanitizers if washing at lower temperatures

There haven't been any good studies on how effective these preventive measures are.

Athlete's foot can usually be treated effectively with creams, gels or sprays that are available from pharmacies without a prescription. These products contain an ingredient that stops the growth of the fungus or kills it.

Home remedies such as tea tree oil or certain herbal foot baths are sometimes recommended. But there's no scientific proof that they are effective in the treatment of athlete's foot.

If athlete's foot can't be treated successfully with creams, gels or sprays, treatment with tablets may be considered. But this is only rarely necessary.

When people are ill or need medical advice, they usually go to see their family doctor first. Read about how to find the right doctor, how to prepare for the appointment and what to remember.