M.M.
I second that -- could be eczema. We use coconut oil (all over his whole body, every day, sometimes twice a day in the winter) and omega vitamins, in addition to free & clear detergent, fabric softener, shampoo, etc. Also make sure you are avoiding any type of "Oxy power" stuff in her clothes or bedding. Oxyclean and any detergent that contains Oxy boost type stuff gives my son an immediate reaction. There is even one free & clear detergent that has the oxy stuff -- still a problem in there.
Last year my son actually got a staph infection in one spot on his arm from the excema getting so bad. If you can, take your daughter to a different ped or even the urgent care to get another opinion. The coconut oil and omega vitamins won't hurt, so maybe try that. It's not an overnight fix -- takes a couple weeks to see results and you have to be consistent.
Good luck!