All I can say is that it sounds like my Katy (Welsh Terrier) but she gets the itchy part as an add on.

Hers is due to a dust mite allergy but that took the skin specialist 18 months to work out. Thankfully her hair has grown back and she only has the occasional breakout and never as badly as the original one when she lost most of her hair. She was on a monthly injection to help but after about 2 years it appears to have lost its strength so we are back to the corozone injection once a month.

I have found Aloe Vera gel helps in her ears when they are giving her problems, but it does make her skin lovely and soft and gets rid of the flaky scabs, which to me look like what we call "cradle cap" which you get on some babies heads shortly after they are born - I remember rubbing slightly warmed olive oil in my daughters head to help lift the flakes of skin off.

Good luck with the search for an answer.