It sounds like she has a staph skin infection which is caused by allergies. I battled that with Lady about six months ago with constant antibiotics until I found the "magic" potion ....... benzol peroxide which is Clearasil. I use the vanishing formula.
I also give Lady baths in Chlorhexaderm, an anti-bacterial shampoo. Her skin is completely clear now with no antibiotics.
Skin Discharge or Odor in Dogs
Here is a before and after picture. You can see some of the pimples that have crusted over in the first picture.