Whiteheads are more common and more likely to become inflamed, because the grease and bacteria that collects can't escape. This causes inflammation. If the blocked hair follicle ruptures, more inflammation occurs, which can lead to nodules and cysts forming. As these disappear they leave behind skin scars. Myths about acne Acne is not caused by poor cleanliness - and certainly isn't infectious.
Many people believe that certain foods, e.g., chocolate, makes their acne worse.
In scientific terms this is generally felt to be a myth. It's a myth that people with acne don't get embarrassed about it, because they do. Many studies have shown this and that people with acne also feel ashamed, lack confidence, and become depressed. The goal with treatment is to prevent skin scarring, to prevent psychological distress, and to shorten the time someone has to put up with acne. Which treatments are used very much depends on how severe the acne is.