I have read that fluoride in toothpastes and mouthwashes can cause perioral acne. I've found toothpaste that doesn't contain fluoride. Also, have read that iodine in salt or foods can flare acne. It seems to be better if I avoid iodized salt.
Dermatologist has given me spironolactone to use for my skin since it seems like the outbreaks i have around jawline and mouth may be hormonal.

I've had bad experiences with cortisone creams on my face, also. Not as severe as yours but caused a reddish, pimply outbreak.