Walking barefoot in wet, dark areas frequented by many other individuals like indoor swimming pool decks, communal showers, and locker rooms result in frequent exposure to pathogenic fungi (dermatophytes) that cause athlete’s foot. Wearing occlusive footwear is thought to play a significant role in the increased frequency of tinea pedis. Exposure to moisture either from excessive sweating or from an external source is a risk factor. Wearing the same shoes and socks for an extended period may damage the skin. Patients with diabetes are predisposed to develop tinea pedis. Some believe that eczema (atopic dermatitis) can predispose one to tinea pedis. It appears that many more men have tinea pedis than women. Pedicure performed in contaminated environments can spread disease.
Treating the feet is not always enough. Once socks or shoes are infested with fungi, wearing them again can reinfect (or further infect) the feet. Socks can be effectively cleaned in the wash by adding bleach or by washing in water 60° C (140° F). Washing with bleach may help with shoes, but the only way to be absolutely certain that one cannot contract the disease again from a particular pair of shoes is to dispose of those shoes.
The fungi (molds) that cause athlete's foot require warmth and moisture to survive and grow. There is an increased risk of infection with exposure to warm, moist environments (e.g., occlusive footwear—shoes or boots that enclose the feet) and in shared humid environments such as communal showers, shared pools, and treatment tubs. Chlorine bleach is a disinfectant and common household cleaner that kills mold. Cleaning surfaces with a chlorine bleach solution prevents the disease from spreading from subsequent contact. Cleaning bathtubs, showers, bathroom floors, sinks, and counters with bleach helps prevent the spread of the disease, including reinfection.
In normal, healthy people, fungal infections of the nails are most commonly caused by fungus that is caught from moist, wet areas. Communal showers, such as those at a gym or swimming pools, are common sources. Going to nail salons that use inadequate sanitization of instruments (such as clippers, filers, and foot tubs) in addition to living with family members who have fungal nails are also risk factors. Athletes have been proven to be more susceptible to nail fungus. This is presumed to be due to the wearing of tight-fitting, sweaty shoes associated with repetitive trauma to the toenails. Having athlete's foot makes it more likely that the fungus will infect your toenails. Repetitive trauma also weakens the nail, which makes the nail more susceptible to fungal infection.