Meeko has the same problem.  Itching behind his ears and scabbing up.  The vet told me he had a "hot spot".  What the... ?  He only does it in one spot.  Why? And what should I do?  The vet told me to comb it out of his hair after a bath and put lots of Neosporin (sorry about the spelling) on it.  And to give him Childrens Benadryl.  It seemed to work for a while, but he keeps doing it and we have to start over.  AAArrrggghhh!  What prevents a Hot Spot?  He has eatten the same food since he was 14 weeks and only now having this problem.  Its not fleas, I had him checked by the vet and by his groomer.  He seems miserable and I want to fix it, but don't know what to do.