What caused this i had it for 4 -5 months (could it of been fast food) I haven't ate fast food in 25 days & the swelling stoped

Allergic Reaction in Face "lipnoids" I believe  ( Right under ears/between neck and face)

and if you think it is the fast food which i ate alot do you know maybe what the chemical could be in the prossed food ? 

thank you in advance