Hello!! Has anything changed with itchies?? I would definitely recommend you try a new food. Nutro is an iffy food to begin with, I have attached a link to claims of Nutro causing deaths!!
Consumer complaints about Nutro Pet Foods
California Natural is a great LOVE ingredient food and made by a superb company called Natura.
I hope you find a cure soon. As for bathing....I bathe once about every 2-3 weeks. More often in the summer.
Good Luck
-Snick & Viv