Itchy Bunny, No Mites

[Wally3]

Hi everyone! I've come here in search of some help!!! I have a seven year old male lop bunny (not sure what specific breed).
This problem started about a month ago. I noticed he had a flaky dandruffy patch inferior to his shoulder area. It got progressively worse which included him scratching and chewing his fur. This has now spread all the way down his spine. He has lost a substantial amount of hair and within the past couple of days has developed black spots on his skin.
I took him to the vet a week ago. The vet did a brush through of his fur and looked at the flakes under a microscope. No mites or parasites present. He then did a skin scraping-same story: no mites or parasites present.
He prescribed an antibiotic and benedryl for two weeks and said it's a possible allergy.
I've been giving him the meds (he hates it) and have not seen much improvement except for a little less itchiness.
I don't know if I should go back to the vet but I am reluctant to do so because it's so expensive!
Has anyone had any experience with these symptoms? Any advice on where to go here?
I have not changed anything about his environment or food...I'm really scratching my head on this one :?

 

[gmas rabbit]

I would get them to treat him for mites. Sometimes they don;t show up and scraping and once treated these type of symptons disappear. You can do it yourself by treating him with revolution or take him and get an injectable type. I know with Derby they couldn;t find anything but once treated the itchness disappeared.

 

[Nancy McClelland]

Sounds like ringworm--one of ours had soapy feeling flakes, growing bald spot and redness at the egdes.

 

[Wally3]

Complete Frustration! I just looked at his ears and it seems he does have mites! I am really annoyed that I had to pay that money for the vet to tell me he didn't have them. Ugh, I will call again tomorrow-I wonder if they will not charge me for a second visit...this is ridiculous!
How can I treat him on my own with Revolution? Do I need the vet to give me this or can I go buy it over the counter?