
Usually not. Most people treat their itchy toes before it spreads. Sometimes the infection spreads to the skin on other parts of the body. These are usually the moist and airless parts of the skin such as the groin. Fungi do not usually go deeper than the skin into the body. However, other germs (bacteria) may enter through the cracked skin of untreated athlete's foot. This can occasionally cause more serious infections of the foot or leg (such as cellulitis of the leg).
The infection sometimes spreads to a nail. This can be treated. However, it takes several weeks of antifungal tablets to clear the infection from a nail. Therefore, it is best to treat athlete's foot as soon as symptoms start.
You can buy an antifungal cream from pharmacies, or get one on prescription. There are various types and brands. For example; terbinafine, clotrimazole, econazole, ketoconazole, miconazole, and sulconazole. These modern creams are good at clearing fungal skin infections.
An antifungal tablet is sometimes prescribed if the infection does not clear with a cream, or if the infection is severe, or if the infection is in many places on the skin in addition to the toes.
You do not need to stay away from work, school or sports. However, try to keep your feet covered in communal changing areas until the rash is gone. Also, try not to scratch the affected skin, as this may spread infection to other sites.