Acne - Description

The medical term for acne is acne vulgaris. It is the most common of all skin diseases, affecting about seventeen million Americans. Acne can occur at any age, but it is most common among adolescents. Nearly 85 percent of people between the ages of twelve and twenty-five develop acne. Up to 20 percent of women over twenty-five develop mild acne. The disease is also sometimes found in newborns.

Acne is a disease of the sebaceous (pronounced see-BAY-shus) glands. These glands lie just beneath the surface of the skin. They produce an oil called sebum, which keeps the skin moist. At puberty, a person's body may begin to produce an excess of sebum. Puberty is the period of life when a person's sex hormones become active. The male sex hormone called androgen causes an over-production of sebum.

When excess sebum combines with dead skin, a hard plug, or comedo (pronounced KO-mee-do), is formed. The comedo can block skin pores. Two types of comedos can occur. They are known as whiteheads and blackheads.

More serious forms of acne develop when bacteria invade blocked pores. A pimple forms when sebum, bacteria, skin cells, and white blood cells are released into tissue around the pore. The pimple may then become inflamed. Inflamed pimples near the skin are called papules. Those that form deeper in the skin are called pustules. The most severe type of acne occurs when cysts (closed sacs) or nodules (hard swellings) form.

Acne often causes scarring of the skin. This occurs when new skin cells form to replace damaged cells. The new skin is usually not formed very easily, causing an unevenness that produces scars. Acne occurs most commonly on the face, chest, shoulders, and back because those are the places that sebaceous cells occur.