The most common type is acne vulgaris, a form prevalent among adolescents. Although its exact cause is not known, it is undoubtedly related both to genetic predisposition and to the increased hormonal activity that occurs at puberty, which causes an overproduction of sebum, the oily secretion of the sebaceous glands. Exposure to external oils and grease (e.g., oil-based cosmetics or hair products, occupational use of cooking oils) can worsen the condition. There is no connection between diet and acne.
Washing the skin removes surface oils and can prevent acne from spreading. The contents of blackheads and pustular lesions should be evacuated only by a physician under proper aseptic conditions to lessen the possibility of scarring. Application of benzoyl peroxide, retinoic acid, azelaic acid, and antibiotics to the skin can clear many cases; exposure to ultraviolet light may also be used. More severe cases of acne may require oral antibiotic treatment. Treatment of the most resistant cases of acne includes the use of isotretinoin (Accutane), a drug that decreases sebaceous secretions. Isotretinoin is a well-established teratogen (i.e., it causes birth defects) and is not given to women who are pregnant. In the past dermabrasion (scraping off of the top layer of skin) was used to improve the appearance of skin scarred by acne, but such severe effects can now be avoided with proper treatment.