Hi. the hair loss that you are having is called Telogen effluvium. It means, hair loss that occurs as a result of stress- physical or mental. You are having a physical stress. Once the follliculitis is corrected, the hair fall will stop in a matter of a couple of weeks, it further takes a couple more weeks for the shed hair to regrow.
All you need to do now is follow & complete the treatment course that your dermatologist has given you. In case the folliculitis is persistent, that you can declare on successful completion of the course, then you must get back to the dermatologist. He will then consider higher antibiotics or further evaluation.