Too much flea meds. Try yeast flakes, b12, and garlic. It can be bought at a health food store, but won't be in a flea section thanks too the FDA. Look under food supplements. and keep that area clean with a wet washcloth, and some very mild baby soap. Be sure to rinse, rinse, rinse. I have groomed dogs for 30 years, and this is the only natural way to not put all that poison into their poor little bodies. Hope it helps.
Hello & welcome to the forum.....You need to have a skin scrape of the crustiness.....This sounds like a ringworm (Which is a fungus) to me.......The balding would fit for this, too.......
However, because the Atopica badly damages the Immune system, it's possible that Mange Mites are taking over which would present w/crustiness & hair loss, also......A skin scrape would determine which disease (If any) is starting to show up.....Treatment is different for both, but both diseases unfortunately, can get out of hand quickly......Let us know what you find out & good luck..... Karla
This could possibly be where the flea allergy has really got him badly? And where there was an itchy sore place now it's scabbing over?
But if this has happened since using the Atopica, then you have to also consider that might be causing it. If you are worried, best to take him to let the vet look at it.