SueHi Laura,
I'm so sorry to hear that your baby is suffering from this terrible rash. My daughter who does have a documented milk protein allergy has a very bad rash on her trunk. I believe it is not itchy otherwise she would cry. It started as cradle cap and she still has severe cradle cap and her hair is thinning a lot. She is also very congested all the time. The ped asked us to apply 1% hydrocorstisone cream and then 2%. Nothing helped. So now I'm applying this ointment called aquaphor that is supposed to moisturise. You might want to try a calamine lotion. I know that for children who get chicken pox , calamine helps to sooth the itching. Coming to the milk allergy part, I still feel that the lactose in the florinef may be causing this congestion and rash in my daughter although her ped does not think so.
Take care. I'm praying for you
T