Hi I Had A Mantoux Test Done Yesterday And Overnight

Hi
I had a Mantoux test done yesterday and overnight the area has become red and inflamed.
I am also experiencing severe discomfort in the form of pain in the arm and itchiness in the injected area.
I was given a BCG vaccine in the left forearm as a kid.
We were tested at my place of work as the Health Dept alerted us that one of our learners was being treated for tuberculosis. The others at work seem to be doing fine.
Please advise.