Acne affects virtually all teenagers at one point or another, to varying degrees. Teen acne is hereditary and is brought on by hormonal changes related to menstrual periods, pregnancy, birth control pills, or stress; oily hair and skin products; certain drugs such as steroids, testosterone, estrogen, and phenytoin; and high levels of humidity or sweating. While acne attacks boys and girls alike, it is worse in boys because they produce more skin oils. However, girls are more likely to seek ou...