In 2015, acne was estimated to affect 633 million people globally, making it the 8th most common disease worldwide.[9][18] Acne commonly occurs in adolescence and affects an estimated 80–90% of teenagers in the Western world.[19][20][21] Lower rates are reported in some rural societies.[21][22] Children and adults may also be affected before and after puberty.[23] Although acne becomes less common in adulthood, it persists in nearly half of affected people into their twenties and thirties and a smaller group continue to have difficulties into their forties.[2]

Benzoyl peroxide is an antibacterial ingredient, and it’s very effective at killing the P. acnes bacteria that causes breakouts. But benzoyl isn’t without its downsides. The leave-on creams and cleansing treatments can dry out sensitive skin types and bleach clothing if you aren’t careful. Board-certified dermatologist Eric Meinhardt, M.D., previously told SELF that it's best to stick to formulations that have no more than 2 percent of benzoyl peroxide listed on the active ingredients chart; stronger concentrations are harder on your skin without being any tougher on bacteria.
Diet. Studies indicate that certain dietary factors, including skim milk and carbohydrate-rich foods — such as bread, bagels and chips — may worsen acne. Chocolate has long been suspected of making acne worse. A small study of 14 men with acne showed that eating chocolate was related to a worsening of symptoms. Further study is needed to examine why this happens and whether people with acne would benefit from following specific dietary restrictions.