Help!!! Itchy baby


What are some remedies for my 3 1/2 week olds itchy skin she has little red bumps on the back of her neck her legs, arms , face, etc. Looks almost like an allergic reaction to something cause around her eyes is red..... 😔 you can’t really tell here but they turn red and she starts fussing badly until I put eurcerin on her and she feels a bit better it’s worse on the back of her neck