Hi fahani,

Is your cat having allergies? Sound like one to me . Anyway, if the skin problem due to fungus, normally the vet will recommend "Melaseb" shampoo. Almost all petshop have this one. I never heard of "Selvazon".

For Melaseb, u only need to use it at trouble area. Use sponge and wet it Melaseb shampoo and apply it at trouble area. Leave it for couple of minutes and wash it. Try to wash it every day or alternate day till the skin recover.

Good luck