What Causes Itchiness Around Nose And Chin After Taking Penicillin For Tonsillitis?

I have tonsillitis and I've been taking Penicillin. It's been about 4 days and my face is a little itchy. I've had an allergic reaction in the past to a certain chap stick so I am pretty certain what one feels like. The itch is comes and goes, sometimes near my chin and others near my nose. Am I allergic to Penicillin? Should I stop taking it?