What Could Flushed, Hot And Painful Cheeks After Getting Injection On Toe Be?

I went to my foot doctor yesterday and got an injection on my left toe. I have had these injections before and afterwards I get very flushed in my cheeks and they get very hot. This time it's only in my right cheek and the cheek bone hurts very badly. I can't sleep and I took 2 benadryl tablets. What could this be?