One of the most common skin conditions of the foot is fungal infection (Athlete's Foot). This is an itchy, red, scaling or sometimes blistering rash. Your podiatrist will be able to determine if the cause is a fungus.
There might be another mimicking disorder appearing like fungus. One such disorder is called sweat retention, which causes deep blistering on the sole of the foot and over the toes, made worse by occlusive footwear. Tests from the affected area show no evidence of fungus.
Elimination of the predisposing factors of heat and perspiration is important in both conditions. Shoes and light cotton socks that allow ventilation should be worn. Occlusive footwear, canvas rubber-soled shoes, and plastic shoes are to be avoided. You should guard against overzealous cleansing with soap and vigorous drying between the toes, which tends to irritate the area.
Transmission of the fungal infection to other individuals is rare. Topical medication as well as oral medications may be indicated.