Acne:
Localized skin inflammation as a result of
overactivity of the oil glands at the base of hair follicles. Acne
happens when oil (sebaceous) glands come to life
around puberty, when these glands are stimulated by male
hormones that are produced in the adrenal glands of both
boys and girls.
The oil glands, which are located just
beneath the skin, continuously produce and secrete oil
through openings in the skin. The oil lubricates and
protects the skin. Under certain circumstances, cells
that are close to the openings of the oil glands block the
openings. This causes a buildup of oil underneath the
skin.
Bacteria, which live in everyone's skin but
generally mind their own business, feast on this oil,
multiply, and cause the surrounding tissues to become
inflamed.
If the inflammation is right near the surface, you get a
pustule; if it's deeper, a papule (pimple); deeper still
and it's a cyst. If the oil breaks though to the surface,
the result is a " whitehead." If the oil becomes oxidized
(that is, acted on by oxygen in the air), the oil changes
from white to black, and the result is a "blackhead."


Acne is also called pimples.