Could Red Spots On Neck And Temple Be Due To Intake Of Stale Yogurt?

Hi , i`m having rash for eating out of date yogurt , i found out that it was expired after i ate 2 yogurt s . Now i have some red spots on my neck and a big one on my temple , The exact description of the "red spots " : Differend forms (they are not round or something) , seems like they have some dots with crust , i think i scrached myself in sleep or something. i want to ask if it`s a rash it heals by herselfe or i need some meds or something ?