White crusty skin

Well as it says my baby’s almost one (on the 10th) and I changed his diaper today right after he pooped and he’s got white crusty skin on the upper part of but crack I’ve been using diaper cream the past few days because he came home from daycare with a soar but and I’m wondering if it could be eczema or maybe a reaction to his diaper cream I tried seeing if it would flake off and he wouldn’t stop moving he doesn’t act like it hurts or anything. I’m just going it’s not anything super serious, and his doctor can’t see him for like a week 🙄😒