Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concern.. As per your complain Athlete s Foot is a fungal infection of feet infecting the webs of toes and fingers of feet.. It can occur due to accumulation of moisture and contamination with socks and clothings.. It can also be contracted with other infected individuals and infected things in salons, swimming pools etc.. It has to be treated with antifungal medications and other home remedies but as Cephalexin is an antibiotic it will not be able to cure fungal infection as it can cure only bacterial infection.. You should avoid wearing very tight shoes and wear cotton socks.. Dust antifungal powder between the toe webs before you wear socks and shoes.. Wash your feet with a mild soap and water and pat dry and apply antifungal ointment like Clotrimazole, ketaconazole etc at night.. You can also soak your feet in a solution of one part vinegar and three parts of water.. Epson salt water soaks can also e helpful.. In case if it still does not resolve you might need oral antifungal medications like oral intake of Terbinafine or Fluconazole.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora..