Dog licking front paw

Question
Our 9 year old Boston Terrier has suddenly developed an obsession with licking his right front paw.  It started when we moved to a new house, so I believe it started out of anxiety and then just grew into a habit (he's very adjusted here, adapted quickly to the new surroundings and is perfectly healthy in every other way.  He still has the energy of a puppy and would play 24 hours a day if we let him.)
Because of the licking, in between his "toes" gets all pink and raw looking.  We took him to the vet on two separate occasions, and each time the vet said it was not infected and there was no sign of fungus or anything, but he prescribed a very expensive antibiotic 'just in case.'  He really didn't give us any other guidance.
We can't keep purchasing this expensive medication, especially since it appears the licking is an obsessive habit that will continue indefinitely if we can't curb it.  
I bought a Contech ProCone soft recovery collar (like a plastic e collar but made of a more flexible canvas material), but it was not suitable for him - although the neck size was correct, it was too wide and was like sticking him inside a dark tube.  
We've used the clear plastic e collars in the past when he's had minor skin irritation on his hind legs from his allergies, but it's hard for him to walk or sleep in it and we have to take it off for him to eat, so I was hoping to find a more comfortable alternative.

Would an e collar be our best solution to keep him from licking his front paw, and if so, is there any alternative to the hard plastic ones?

If the e collar is not a good solution for this issue, is there anything else you might recommend?

Thanks in advance for your help!

Answer
When dogs lick their paws a lot it is often because of an allergy to something.  If it is causing sores on the feet and lower legs, then it could be an obsessive compulsive disease called acral lick granuloma.  Ask your vet if your dog can have a short course of steroids to see if it takes away this licking.  If it does, then it is most likely an allery to something.