pls stay away from powders as it contains talc and it can cause the rash to become worse. u can get some creams from the pd and apply some lotion to the area. clean the area from sweat or milk spills and make sure the area is kept dry at all times. it will slowly heal.
Use Aveeno to clean the area and ensure skin is gently wiped dry. Try Ceradan or Atopalm lotion on the area. If that still doesn't work, best to bring to a doctor to check. Hope she will be OK soon!
I use diaper cream for rashes like this. It helps. Just a small amount and spread throughout the neck.
best to bring your baby to the pediatrician
Put moisturizer. It helps (: