The approach to acne treatment underwent significant changes during the twentieth century. Retinoids were introduced as a medical treatment for acne in 1943.[83] Benzoyl peroxide was first proposed as a treatment in 1958 and has been routinely used for this purpose since the 1960s.[168] Acne treatment was modified in the 1950s with the introduction of oral tetracycline antibiotics (such as minocycline). These reinforced the idea amongst dermatologists that bacterial growth on the skin plays an important role in causing acne.[164] Subsequently, in the 1970s tretinoin (original trade name Retin A) was found to be an effective treatment.[169] The development of oral isotretinoin (sold as Accutane and Roaccutane) followed in 1980.[170] After its introduction in the United States it was recognized as a medication highly likely to cause birth defects if taken during pregnancy. In the United States, more than 2,000 women became pregnant while taking isotretinoin between 1982 and 2003, with most pregnancies ending in abortion or miscarriage. About 160 babies were born with birth defects.[171][172]
Acne appears when a pore in our skin clogs. This clog begins with dead skin cells. Normally, dead skin cells rise to surface of the pore, and the body sheds the cells. When the body starts to make lots of sebum (see-bum), oil that keeps our skin from drying out, the dead skin cells can stick together inside the pore. Instead of rising to the surface, the cells become trapped inside the pore.
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.