Could be from the bacteria on their hands or could be the bacteria we all have on our skin. They didn't have me wash my face before or afterwards. My doctor said that once the hair is plucked it leaves a space which is just begging to be filled with bacteria. I washed my face thoroughly once I got home. It really did suck. The people at work said that if they didn't know me before, they would have thought I had a bad case of cystic acne. I'm left a little scared from the experience but using Retin-A has helped that thank goodness.