Red cheaks/chin on 7 month old

First off, I will be calling his ped in the morning.

Second, please ignore the airbrushed look in this picture, I can't get this stupid filter off of my camera. Also ignore his angry face, its bed time and he did not want to be put down 🙃

He has had this red rash on his cheaks and chin for 2 days and I have no idea what it is. Its not from food, I dont think he is teething. It has a dry texture on it as well. You can see the redness on his cheaks (left one is worse) his chin and a little on his nose. My camera won't pick up the texture though. Its worse in the afternoon/evening and gets a little better in the mornings.

His wet diapers have also decreased, he can go 3 hours with a totally dry diaper like all day long and when he does pee its very little. I have been trying to feed him more and have been offering water but he refuses the water.

I was thinking maybe a viral infection but other than these two issues he is acting and seems totally fine. Again, calling his ped first thing in the morning just wanted to see if anyone had any ideas.