It is possible that is is food allergies, but it could also be environmental. The bumps on the chin sound like chin acne from her chin staying moist after drinking or slobbering all over a toy. A lot of bullies cannot handle grains contained within a lot of the foods, and while Fromms Duck and Sweet Potato is a great food it is not grain free which could be causing the issues you are seeing. Holistic Select is another decent grain free brand that our breeder used with good results, but it is not something we have tried as my baby has some interesting food allergies and we are currently on a modified home cooked diet for her. All in all with what you describe I would consider switching to a grain free food and go from there.