There are times when you are working with a client that you will find severe cases of acne that nothing will seem to clear up.   It may be that it needs to be treated with a High Frequency Esthetician Machine.  This machine will emit high frequency impulses, and yes there is a buzz, that will generate heat and kill the bacteria causing the infection.   It will also massage the skin and help restore proper blood flow in the area of the infection.  It is best used in a circular motion and in segments of three to five minutes on and around the affected area.