How Can Persistent Foot Skin Infection Be Treated?

Hi doc, i have skin infection in my right foot. i showed to skin specialist but did not cure,then again i show to my routine doctor he prescribed cotarly cream for dry skin still infection did not cure, i have infection from 6 months or more then. skin specialist said it not because of fungal infection but something else i want to know is there any cure for this kind of skin problem or infection. i am afraid this should not spread all over the foot. plese suggest?