As a pale person, my skin turns red a lot easy (and so does both my babies). I wouldn’t call it an allergy but more of a reaction. I’d just watch it and see if it bothers him or if it gets worse.
Sometimes my guy gets splotchy like that too even after foods he’s had before! I’m sure their body is still adjusting to the foods
https://www.instagram.com/p/C6YUbxbPsRB/?igsh=MzRlODBiNWFlZA==
raspberry could leave a contact rash from acidity, doesn’t necessarily mean an allergic reaction! just keep your eye on it
He also rubs his face on the floor and becomes red super easily