i have had to deal with mange mites before in guinea pigs. i found it quite easy actually. i found this terrific spray that you put on them and after a couple of days the mange was gone. it took longer for the scabs to heal. I dont remember the brand as a haven't had to use it for ages, i will see if i can find it on the internet.

I have had a couple of guinea pigs who also had sensitive skin. they looked like they had mange but it was something that they had had since i got them. poor things. i just had to make sure that there skin was always moisturised in the dry spots. sorbolene cream works well. also you could get some quartazone cream from the vet if it is just dryish skin.

I also wash them with a eucalyputus pet shampoo now and it seems to keep their coats nice. i haven't had a problem with mange since i started using it.