5 yr old obsessively scratching

Question
We have a five yr old Dachshund who we have had from birth.  He has been delightful to have without any major problems.  About 3 1/2 wks ago he began scratching his ear & neck (under his chin) and finally scratched his neck so bad it started a "hot spot"  He was unable to stop scratching without just holding him. The vet gave him a cortisone inj., placed him on prednisone, antibiotic, benadryl q8hrs, topical antibiotic, & elavil. He said the ear was not infected, canal looked good.  He has been back to the vet 3 times, as this will not stop. We eventually got a cone so he couldn't reach the area, but now just scratches his left side below the area. It looks like he tries not to scratch, as his back leg will shake uncontrollably, and he places his head on the floor. The vet has done all types of skin tests, which are all negative. we noticed that now if he gets scared or upset his back leg will tremble and he will begin scratching this area. There appears to be an emotional component to this ,but we do not know what to do. Sometimes deversion helps, sometimes not. He has gotten where he likes the cone & prefers it. He is off prednisone, but continues Elavil & benedryl. He has always been a little OCD, licking the carpet & sneezing over and over again, but nothing alarming.  My husband & I work out of the home,traveling at times. This doesn't appear to bother him, though our schedules are not consistant. We dont know what happened or what we could have done that may have triggered this.  Have you seen this before? We would appreciate any advise that you can give us. Oddly,one thing that helps tremendously is if he watches cartoons. He will lie in his bed quitely watching cartoons & not scratch.????Thanks so much for any help you can provide!
Sheri

Answer
The 1st thing that comes to my mind is flea allergy - it only takes one flea to bite to set it off.  Have you tried doing oatmeal baths?  You can also try Rescue Remedy (found in health food stores, some grocery stores, etc.) to help him relax and feel calmer - it is natural and has no side effects.  Has he had a change in food?  Change in flea preventative?  Have you tried rubbing Vitamin E on the spots?  You might want to consider an all natural food with no by products or preservatives.  Some of them are really good for skin and coat.  Sneezing over and over can be a sign of allergies or other issues.  You can also try salmon oil for dogs in the pet store.  That helps with skin and coat.  These are some suggestions to consider.  I had a dog that always licked the floor, the bed, anything and there was nothing I could do to stop it.  He got worse when he got sick.  Hope this helps!