I don't think it is psoriasis. It is not white or flaky, although it did develop on dry elbow skin. It has been almost 3 days now and it appears to be healing (not as red).
That sounds exactly like how my psoriasis started. If you develop thick white skin or flaky skin, that's what it is. Nothing helps mine except psoriasin topical gel. It smells like pine tar & you have to use it a couple times a day, but it helps.
Psoriasis is an auto-immune disorder & stress agitates it. Potent green drinks like Green Vibrance help too. Good luck!
Could have started off with an friction abrasion that you scratched unknowingly and now is slightly irritated.