LO is 6 weeks and has normal baby acne, but in the past week has been developing rashy patches on his face, a little bit on his neck and shoulders. They aren't scaly and look similar to hives . Last night when I got up to nurse him it looked pretty bad; very red blotches over his eyelids and other various spots on his face. It seemed to fade over the course of a half hour but since then comes back, then fades again slightly.
I haven't changed our detergent. I don't wear perfumes or put lotions on him. It's not baby acne. Does this sound familiar to anyone? I'm feeling pretty helpless and can't see the pedi until the morning. LO seems very uncomfy.

I thought maybe heat rash or an allergy? It's not terribly hot out but it seemed slightly better when I stripped him down. And it seems to get worse when I nurse him (bf).
Re: Help! Any ideas?
This is the link I found most helpful: https://www.medicinenet.com/script/main/mobileart.asp?articlekey=95365