If you've ever visited a mushroom farm, you'll know that mushrooms, like any fungus, prefer dark, moist conditions. The inside of your shoe is paradise for a fungus. Both your feet produce about half a pint of sweat every day, more than enough for a thriving fungal population. A fungus is a type of plant and sends out tiny roots in search of water. A foot fungus condition makes the skin look dry and cracked as the plant draws water out of the surrounding skin. It can also grow on toenails, causing them to appear discolored. You may also notice an odor. The first step in treating foot fungus is to take away its water supply. Wash your feet daily and dry them thoroughly, especially between the toes. Most of the antifungal creams available work well against common foot fungus. If the condition doesn't improve within a couple weeks, consult a foot specialist in your area for more effective treatments.