Causes of Foot Fungus

Foot fungus, often also called athlete's foot, is a specific kind of fungi that grows on the outer layer of skin. The fungi are called dermatophytes and they need moist, sealed environments to flourish. The fungi are also contagious.

The Way It's Spread

Athlete's foot is spread in three ways: pets to human, contact with an infected surface, and skin-to-skin contact. With skin-to-skin contact the fungus is spread when an infected person touches an uninfected person. The infected person may not know they have the virus because they may not have symptoms or signs of an infection at the time of spreading the fungus.

The fungi are surprisingly strong and can survive on almost any surface including floors, bed linens, shoes, rugs and mats. It gets spread when someone touches the surface. Public places are especially bad for spreading the fungi so it's important to wear foot protection in places like swimming pools, communal baths, saunas and locker rooms.

Most people don't realize that pets can spread the fungus to humans. Many household pets can transmit foot fungi as well as other bacteria.


Once the foot fungus has been transferred to the skin on your feet, you will experience scaling, flaking and itching. Sometimes the skin will blister or crack causing raw tissue that can be very painful. Extreme cases of athlete's foot can cause significant swelling and inflammation. If the tissue becomes raw, there's always the chance of a secondary bacterial infection.

Foot fungus can cover the entire foot and sometimes the same fungi that causes athlete's foot can be spread to other areas of the body including the groin and other parts of the body. When this happens, the infection is called a different name like dhobi itch or jock itch.

Some people have complications like an allergic reaction to the fungi. The allergic reaction shows up in the form of vesicles or blisters on the arms, chest and hands.

Diagnosis and Treatment

Often a diagnosis can be made by a visual inspection. But if the case of foot fungus is severe, a doctor may complete a microscopy of potassium hydroxide where skin scrapings are collected and exposed to potassium chloride. Occasionally a biopsy is required.

Treatment involves over-the-counter or prescription topical creams. Sometimes antibiotics are prescribed for secondary infections. If the athlete's foot is caused by excessive sweating, medication may be prescribed to help reduce the sweating.


Wear footwear like a cheap pair of sandals when walking on moist public floors like pools and showers. Don't share towels. Keep footwear and feet as dry as possible to reduce the chance of the fungus thriving even if you do come into contact with it.