I noticed it on her face yesterday but now it looks like it’s on the back of her neck and it appeared on her shoulders this morning. I used baby shea moisture shampoo on her last night but I’ve used it once before and she was fine. She has been spitting up here and there and it was on her onesie yesterday for a little bit on the shoulder area until I could get her changed. Do

You think any of those things could be it? I haven’t changed detergents for her or my husband and I so I don’t think it’s that unless she just randomly became sensitive to it.