THE
ANATOMY AND CAUSES OF ACNE
There are tiny hair follicles on our face, chest, and back.
This soft and short hair, called vellus hair, is invisible
to the eye but if you run your hand softly on your cheek
for instance, you may feel it. Each tiny hair has a gland
underneath the skin containing sebum, a mixture of
fat and water that keeps our skin moist and soft. Glands
that produce sebum are known as sebaceous glands.
Acne
occurs when these hair follicles are plugged with the sebum
and dead skin, allowing a perfect reservoir for one particular
type of bacteria, Propionibacterium acnes (P acnes),
to grow within the small hair site.
What
causes acne?
Many
things can contribute to the formation of acne: genetics,
hormones, stress, too much friction against skin (sweat
bands and helmet straps), exposure to oils and grease, cosmetics,
and medications (anabolic steroids, corticosteroids, Lithium,
Isoniazid). Dirt and chocolate don't cause acne - see our
acne myths section. Below
are some of the more common causes that can cause acne:
Hormones
It
is very common for both men and women to start getting acne
when they hit puberty. Our adrenal glands start producing
lots of hormones when we reach puberty. Rising levels of
these hormones, in particular androgens (or male hormones),
causes our sebaceous glands to enlarge and produce more
sebum, increasing the chance of blockage and therefore acne
formation. It is known that sebum secretion peaks during
adolescence and declines after 20 years of age. So, for
many people, acne seems to "disappear" when they enter their
20s.
Bacteria
Propionibacterium
acnes is a normal inhabitant of human skin, and it uses
the sebum as food. Therefore, the more sebum around, the
more P. acne can grow. In addition, research shows
that some individuals have higher counts of this bacterium
in their skin, potentially resulting in more acne.
Genetics
Research
shows that in severe cases of acne, there may be a genetic
predisposition. However, no direct link has been made and
one cannot predict the severity of acne based on a family
history of acne.
PMS
In
some young women, acne is a component of the premenstrual
syndrome and is due to flare-up of hormones at the time.
Environment
Acne
can be caused by constant exposure to grease at work (auto
repair shops or fast food restaurants).
