Grapes are new-ish to him. He's had them a couple times but I've never seen this reaction before.
How long ago did he eat them?
About 10 mins before I took this pic. I was washing his face off from lunch and I noticed the rash. I put some auqaphor on it and it looks a little better now.
Is he drooling from teething? DS used to get rashes from that. I put aquaphor on in the morning and before bed. If that works to clear it up, keep doing it before bed to prevent it from coming back. DS drooled a LOT while teething.