I know allergies can be sooo frustrating
I battled it for many years.
Try the elimation type diet, taking away all the treats and giving them back slowly one at a time.
Maybe try a different food...
Try salmon oil...
Hypoallergenic shampoos, or oatmeal shampoos...
A general blood test to test for hypothyroidism, etc...
Only using water/vinegar to wash your floors...
Try things one at a time, and not all at once so you can get an idea of what bothers her.
If things get REALLY bad, like if shes itching her hair out and chewing her skin raw, consult your Vet about using benedryl to help calm her down. But I really wouldnt suggest using benedryl or any other medication to "solve" this problem, but just a short term fix while you try to figure it out.
Goodluck!