Maybe try feeding him a garlic fly supplement. After a few weeks, the garlic will build up to a level where he will no longer be tasty to the bugs. It may keep him from being bitten as much as his is.
For the more intensive itchy areas, (with my guy it's his belly) I use extra strength anti-itch hydrocortizone cream. Seems to work better than the other 137 things I tried over the past few years.