My Jack Russell has a severe skin problem

Question
I have a 7 year old Jack Russell named Ginger. About 2 years ago she was outside and we heard her yelp so we went out to see what she was doing.  She had found and killed a mole. And we didn't see any marks on her but a few days after her leg was swollen, a lot of the hair was gone, and it was all scraped and bloody because she wouldn't quit itching it.  We took her to the vet and after trying numerous steroroids and antibiotics nothing helped.  We took her to another vet and he said it was a yeast infection so we gave her 1 spoonful of yogurt each day for about 3 months.  It started to clear up but eventually the yogurt stopped working and she was still itching.  A few months later we took her back to the vet and he suggested lyme disease but after spending 300 dollars to check for every disease carried by a tick the  traces of lyme disease were so low that the vet said not to worry about that.  She is getting older and I want to be able to play with her before it's too late.  She has been in one of those cone collars to keep her from licking her leg for 2 years and she is miserable, but she won't stop licking and scratching.  I don't want to have to spend 1000 dollars to find what is going on and I am losing faith in our vet.  I love Ginger and I want to see her happy again.  What could be wrong?  

Answer
that just sounds like sever allergies that would be treated with steriods which should have helped. I give my Boston terrier who is 1 year old that has allergies one  BENADRYL 25 ML pink people allergy pill every 12 to 24 hours my vet had recomended these cheap pills to me when my Jack russell terreir had allergy problems at 10 months of age he is now 2 and really hasnt been bothered that much with allergies since I changed him and my Boston terrier to Blue Buffalo Fish and sweet potatoe diet. I reccomend the alelrgy pills but only ever give them 12 hours apart giving them closer together wont nessairy hurt the dog but will likely make the dog very sleepy and misrable...my dogs experianced some drowsiness when they were first on the pills but after awhile they just werent getting drowsy anymore...I've had my JRT on and ioff the Benadryl caplets several times without ill effects. I also reccomend filling a large  rubbermaid bin large enough to bath the dog in or a large cat litter pan thats never been used again large enough to bath the dog...fill it with cool not warm water but not cold water either and place about a cup of fresh eatting/baking oatmeal in the watr mix it around for a minute and then get the dog and put her in...take a cup or tiny container and pour the oatmeal water over her from neck to toe always leave the head for last they seem to just hate it when there head gets wet! this is a very soothing bath and I've persoanly done it with both of my small dogs to ease there itching, after you've poured the water over her for about 5/10 minutes you can use cool fresh tap water to rinse her. Also you can always bandage her legs when its not overly hot out and place something storng on the badages like hot sauce/bitter apple spray/viniger so the cone can come off sometiems but only ever do this when your there to watch as Jacks are famus or at lest mine is for removing bandages. If the skin gets scratched up and raw again its nice to use cool compresses...just some wet paper towel wetted with cold water and press them onto the hot rashy areas this gives the dog some realeaf as well. And if the skin is really scarred up some Poly sporn of generic brand healing onitment helps to heal the skin as well. Thats so far about all i know about allergies. I hope some of this can be of soem advantage to you and hope you dog has a good quaility of life in her senor years.