Hi Silly,
I will let you know what Rosie says, unfortunately I'm very green and have little experience in skin conditions as until this year we'd neve had an issue, so am totally relying on our great vet when we see her with Meggy Moo on Wednesday. I will update Megan's thread with the advice given.. I know Mites can be treated orally, topicallly with drops or injections and varying types of fungal respond to different anti fungal creams and shampoos. From what I've read mites comes in cycles hence why the treatment is spaced out.
It may be worth starting a thread for your piggies so you can keep everything in one place, it helps as more experienced members find all the info they need about your piggie as opposed to digging around in various threads.
To start a new thread once in the Health and Illness section click on +Postnewthread button on top left of page, hope that helps.
I hope your piggies recover soon