Whiteheads look like small white bumps and are usually about the
size of a pinhead. They form under the skin as the follicles become
more and more clogged and enlarged. Whiteheads never reach the
skin’s surface or open up. Therefore, they are called closed comedones.
Blackheads, on the other hand, are closed comedones that continue
to grow upward until they break through the skin’s surface.
At this point, the enlarged hair follicle is visible and open to
the skin’s surface. For this reason, blackheads are known as open
comedones.
To the naked eye the contents of an open comedone look black.
The black color is the result of oxidation, a process of discoloration
that occurs when dead cells, sebum, and bacteria mix with oxygen
in the air. However, some people mistakenly think that dirt trapped
under the skin causes an open comedone to appear black. Ayoung
man recalls how this misconception affected him: “I had blackheads
all over my forehead and nose. I scrubbed my face constantly,
trying to scrub the dirt out of those blackheads. But I kept getting
more. I couldn’t understand where all the dirt was coming from.”
Since comedones do not form as a result of severe inflammation,
they are not painful, no matter whether they are blackheads or
whiteheads. Moreover, because comedones are not large, red, or
pus filled, when seen from a distance, the skin of people with comedones,
especially those with whiteheads, appears relatively clear.
However, because comedones are enlarged, clogged follicles, they
do not disappear until the follicles unclog. This may not occur under
normal circumstances until sebum production decreases or the
patient receives effective acne treatment. Therefore, whiteheads and
blackheads often stay on or under the skin for a long time.
Even more troubling, some closed comedones do not grow upward
and become open comedones. Instead, as they become more
and more packed with sebum, they grow downward under the surface
of the skin and continue to enlarge until they burst. This results
in the formation of more serious acne lesions such as papulesand pustules.
