Acne is a skin disorder that occurs most commonly among teenagers. It consists of various kinds of blemishes, mainly on the face, upper chest, and back. A few blemishes are normal, but severe acne may result in permanent scarring. Some teenagers find severe acne so distressing that they develop emotional problems.
In most cases, acne appears during early adolescence—at about the age of 13, when a child starts to develop physically into an adult. This development is controlled by chemical substances called hormones . One kind of hormone stimulates the oil glands in the skin. These glands, which are called sebaceous glands, grow larger and produce more oil. Each sebaceous gland empties into a hair follicle, a cylinderlike structure that surrounds a hair. Normally, the oil empties out of the follicle through a pore that opens onto the skin surface.
Sometimes the pores become plugged and oil accumulates under the plugs. A plugged pore forms a blemish called a blackhead or whitehead. The black color of a blackhead comes from a normal skin pigment that darkens when exposed to air. A whitehead develops if a pore is so clogged that no air can enter.
Small, pus-filled bumps called pimples , or tender red lumps called cysts , may also develop. In pimples and cysts, a type of bacteria called Propionibacterium acnes breeds in the follicles, sebaceous glands, and backed-up oil, producing inflammation that causes the redness and pus. Cysts may leave permanent scars, but pimples usually do not scar unless squeezed or picked.
A poor diet, worry, and various bad habits are often blamed for acne, but they have little to do with the disorder. A balanced diet, enough sleep and exercise, and regular washing are good for the complexion and general health but cannot prevent or cure acne. Mild acne can be treated with nonprescription lotions that contain benzoyl peroxide or other medications. Heavy makeup makes acne worse and should not be used.
Severe acne should be treated by a physician. An antibiotic called tetracycline may be prescribed. This drug blocks the growth and reproduction of Propionibacterium acnes bacteria. Medications containing vitamin A acid may be applied to the skin to help prevent new blemishes. Other treatment used by doctors includes removing blackheads, freezing the skin with dry ice or liquid nitrogen to make it peel, and using a sun lamp. A drug called isotretinoin may be used to treat severe acne. But this drug, which has the trade name Accutane, can cause birth defects. It should not be used by women who are pregnant or who may become pregnant while undergoing treatment.
