[CC's]

The shampoo your vet gave you should do the same thing as the human shampoo's I mentioned. I would only use human shampoos for something like this if I didn't have the vets shampoo. Its different than everyday care needed for the coat.

Don't be afraid to bath her every couple days for a while to get it under control. The caps your vet gave you also are about the same so I would continue his advise and maybe switch her to a food for allergies like Lamb and Rice or Beef and rice. Stay away from corns, and wheats.

Get her off the Eukanuba. Try Natural balance duck and potato, lamb and rice or venision and brown rice. Also Nutro natural choice has a lamb and rice. You can find these foods at Petco.
There are others out there as well but these are the ones I know to find easily.
No table scraps or milk bones (only her food) till you see if the food change helps. It takes 6 weeks for that to really make a change in the system.

Seborrhea is when the oil glands go wild and it causes greasy, smelly skin and itchiness. Sometimes the skin can even get a waxy feel.
They can get a rash if the pores get clogged to.