Baby rash? Eczema? Help!

Isabel
So recently my daughter broke out with this rash (I know talk to the doctor, I called but they're making me wait until Wednesday to even talk to the nurse over phone first, so I need some opinions from you guys first please!) she's had it for about a week now but just today it's gotten really bad. She's 11 and a half months, I just started her on 1% milk recently, she's been eating everything but eggs and nuts/peanuts, the whole house has carpet, a while ago I put on a dress on her that wasn't washed by baby detergent. Just wondering if any of those could be factors of a rash, or if it's eczema, or anything else? Please help! I will be going to a doctor next week but before that I'd like to know if any of you have experienced this before with your baby?