Kristy
Hi! I know how frustrating it is to have a dog with allergies. I have an 8 yr old Y. Lab, who scratches,bites and gets recurring ear infections - all from allergies.
I would try to see if its a food allergy first. YOur vet should have told you how to do this. Reese needs to be put on "non-allergenic" food ie. fish & potato, deer & potato, etc. - you generally can only get this from the vet's office (may be by science diet?) You feed the dog only this for 30-60 days (no treats - unless they are non-allergenic) - you monitor closely any changes (less scratching, biting, etc) then you start to slowly introduce the food you are currently using & see what happens - if she starts to scratch, itch - you know she has food allergies - Beleive me - that would be the easiest - you would just give her food she does not have symptons with.
IF NOT - you can do an allergy test - I finally did this for my dog 2 yrs ago (as I knew it wasn't a food allergy) Depending on you vet - it will cost you!! I finally had it done @ Banfield (in Petsmart) because it was ONLY $400 (cheapest by far) I pretty much knew what the outcome would be - he's allergic to certain weeds, mold, etc. Nothing I could control. So after several years and a lot of money (spent $2500+ in one yr just on cortizone shots, meds etc) - I give him a Benedryl or Chlotrimetron (from Walmart - just like people) & it gives him as much relief as steroids, meds, etc. & costs very little. I also used a product called Dinovite (you add to food) that I found on the web - a lot of people had success w/it & my dog's coat looked great) - but it started to get too expensive. I also use Vet solutions Aloe Vera shampoo & bathe him every 7-10 days, wash his bedding once a week in HOT water. He is not itch free - but his coat is thick and shiny & it's not half as bad as it was.
Good Luck - hope you find a cure soon
K.