From Encyclopedia of Sex and Sexuality
A dermatological (skin) disorder that develops to some extent in almost 90 percent of male and female adolescents. Since adolescents can feel anxious about their appearance under the best of circumstances, many boys and girls consider acne to be a serious social and personal matter. It is important that adults treat the adolescent with sensitivity and concern, recognizing that acne is generally at its worst from sixteen to nineteen years of age in males and from fourteen to sixteen years of age in females.
While males and females may continue to experience acne-related conditions for ten to fifteen years after the first episode, the frequency, duration, and intensity of episodes generally decline in the late teens and early twenties. Males tend to have more serious acne for a shorter period of time, and females tend to have less serious acne for a longer period of time.
 Biological Causes of Pimples, Acne, and Other Skin Eruptions
Pilosebaceous units, or oil glands, are a type of sebaceous gland with extremely tiny hairs. As might be expected, they are most heavily distributed in the face, neck, and upper body, where most acne occurs.
These glands are present throughout childhood and early adolescence, but they do not become the sites for acne until the adrenal and gonadal glands (testicles and ovaries) begin to secrete androgenic (male) hormones. Sebaceous glands are sensitive to stimulation from the androgen-sensitive hair follicles, and secrete lipids (fats) to lubricate the skin. They also secrete sebum, an oily semi-liquid substance, which is then excreted through a duct to a pore, or opening, in the skin. When there is an increase in the production of androgenic hormones, the content and volume of the sebum secreted through the pore can change. This change can facilitate the entry and colonization of the sebum by bacteria. Additional yeast development can result in thickening and inflammation of the skin, and the development of blackheads. Blackheads develop because the sebum turns black when it comes into contact with oxygen. Whiteheads develop when the sebum gets trapped below the thin surface of the skin and rises to form light-colored bumps.
Blackheads and whiteheads can become infected if the sebum stays blocked in the pore. This happens because sebum accumulates there, causing pressure and irritation, a process more likely to result in pimples—bumps on the skin that develop when bacteria and yeast grow in whiteheads or blackheads. Bacteria can also cause pus to develop, and this, in turn, causes pressure and inflammation around the pimple. The infected area can be tender and painful to touch, but the nature and severity of these episodes vary widely from person to person.
It is true that acne can “run in families,” but it is equally true that each person is unique and has his or her own genetic make-up. A parent’s experience with acne will not necessarily help an adolescent predict whether he or she will share a similar experience.
Acne can develop in a variety of ways, and it affects males and females somewhat differently. Since it does affect almost 90 percent of both males and females, it is usually considered a normal sign of adolescence.
 Treatment of Acne
Most adolescents use over-the-counter medications to treat episodes of acne. It is extremely important that the directions be followed precisely and a doctor be consulted when necessary. Many adolescents use medications recommended by friends, but these may not be appropriate for their skin type, skin color, or specific acne condition.
In general it is recommended that the adolescent wash his or her face with a mild soap no more than three times a day. Excessive face-washing can cause skin inflammation. The individual should wash with hot water to open the pores, and rinse with colder water to close the pores. It also helps to use only a clean pillow-case and sheets and to avoid skin moisturizers that clog the pores and contribute to the outbreak of acne. Washing oily hair and keeping hair off the face is another method of preventing some outbreaks of acne.
There is absolutely no evidence that any particular foods cause people to experience acne, so diet management to control it is generally unsuccessful. Some individuals may have specific skin reactions to particular foods, but there is no relationship between acne episodes and the intake of chocolate, soda, oily, or other foods.
There is strong evidence that the usual emotional stresses associated with adolescence can affect outbreaks of acne. This explains why people apparently develop pimples, blackheads, and whiteheads before important examinations, social events, and in other exciting or anxiety-producing times. Stress-management techniques, including biofeedback and relaxation, can be helpful to adolescents who experience stress-related episodes of acne.
Other treatments are available through physicians who specialize in dermatology. Dermatologists may prescribe antibiotics or topical ointments with retinoic acid.
The overwhelming majority of adolescents experience some degree of acne at some time. Parents can make these episodes easier for their sons and daughters by treating adolescent concerns with respect and understanding. If it seems that the acne is unusually troublesome or may result in scarring that threatens to disfigure the young man or woman, medical care should be sought.