Will It Be Safe To Use Lamasil Cream For Tinea?

yes my 7year old daughter keeps getting tinea in the genital area, the dr had me use a lamasil cream, it will work after a couple weeks then it comes back and this time it is real bad almost blistery looking i went and got powder form thinking it would keep it dryer than the cream but its not getting any better. is there something else i can do to make it go away for good.. natural remedy maybe or an oral that will kill it .