How to get rid of rashes around 3-4 months old baby's neck?

last time i apply corticosteroid thinly for afew days and after the skin heals completely then maintain with cream. i know most people are against steroid cream but its the fastest way to heal. (usually 2 -3 days). occasionally will still have rash so i will still use it. my son is now 25months old. btw my son has eczema and is prone to heat rash. see a PD and they will advice accordingly.