Athlete's foot is a skin infection caused by fungus. A fungal infection may occur on any part of the body; on the foot, it is called athlete’s foot, or tinea pedis. Fungus commonly attacks the feet because it thrives in a dark, moist and warm environment, such as a shoe or boot.
Fungal infections are more common in warm weather when feet tend to sweat more. Fungus thrives in damp areas, such as swimming pools, showers and locker rooms. Many workers often have sweaty feet and use facilities where fungus is commonly found, thus the term "athlete's foot."
Athlete's foot usually produces itchy, dry, scaling skin. It is commonly seen on the soles of the feet and in between the toes. In advanced cases, inflammation, cracks and blisters may form; an infection caused by bacteria can also result. The fungus can spread to other areas of the body, including toenails.
Avoiding walking barefoot combined with good foot hygiene can help reduce the spread of the fungus. Feet should be washed every day with soap and water and thoroughly dried, including between the toes. Feet should be kept as dry as possible. If your feet sweat a lot you may need to change your socks during the day. Antifungal powders, sprays and/or creams are often used to treat athlete's foot. Your foot and ankle surgeon will recommend the best treatment for you.
Source: Foot Health Facts, American College of Foot and Ankle Surgeons® https://www.foothealthfacts.org/conditions/athlete-s-foot