Dr. Nicholas Perricone, MD, is a dermatologist who has written several books, primarily on the subjects of weight loss and maintaining the appearance of youth. Dr. Perricone is an Adjunct Professor of Medicine at Michigan State University’s College of Human Medicine, from which he received his MD. He has appeared in two special programs on PBS. Dr. Perricone sells his own line of skin care products. Perricone presents himself as a radical in the dermatological community, repeatedly encouraging his audience to challenge the status quo. He compares his work relating diet to skin care with Ignaz Semmelweis's work on hand washing and the spread of disease in the 1800s.