Being a diligent student that I am, I feel that it is essential to educate myself on the science behind acne before attempting to develop a regiment that works for my skin. Of course, I am already familiar with the basic scenario, which, I believe, goes pretty much like this: the pore gets blocked, and depending on how lucky you’re, you end up with a blackhead, a whitehead, or a giant, obnoxious zit. This is all fine and dandy, but can anyone please tell me why exactly does it happen? After all, there are plenty of those lucky bastards whose pores never ever get clogged even though they almost completely neglect their faces. “It’s all about excessive oil production,” you might say. Ok, but what about all those people with oily faces who do not suffer from adult acne. My mom’s face, for instance, has been pretty much leaking oil for all of her life, and yet she said good-bye to her breakouts once her teenage years were over. What I am getting at is that properly functioning adult skin is not supposed to produce acne, no matter how oily it is. Period. So what gives? Why does my (and possible your) acne refuse to budge?
The Anatomy of a Pimple
I’m sure many of you have seen this diagram multiple times, but let’s go over it again. Pilosebaceous unit consists of central canal, called the follicle, and opening to the central canal, called the pore. The follicle, in turn, contains hair shaft and an oil gland, known as sebaceous gland. Technically, a pimple can form wherever there is a pilosebaceous unit on your skin, which is pretty much everywhere except for a few hairless patches, such as palms of our hands and soles of our feet. Because all of your face is covered with tiny (and at times not so tiny) hairs and has very hard working sebaceous glans, it is a perfect place for pimple infestation.
Types of Pimples
In medical jargon, zits, spots, pimples, blemishes, blackheads and whiteheads are all officially referred to as “comedones”. Comedones come in two forms: open and closed. In case of open comedones, more commonly known is blackheads, the pore remains open to the skin surface, but becomes enlarged and blocked with excessive skin oil and dead cells from inside the central canal of pilosebaceous unit. In contrast, closed comedones, known as whiteheads become blocked to the outside skin. In fact, those nasty red bumps of various sizes that are ruining your life are nothing more than closed comedones, which could have been relatively harmless whiteheads had they not got inflamed.
The Proximate Cause of Acne
The proximate causes of acne are what we’ve been hearing about for the past 40 years or so. There are four of them: 1) blockage of the pore, 2) excessive production of skin oil, 3) bacteria colonization that leads to the infection of the pimple, 4) inflammation of the pimple and surrounding tissue. Let’s look closely at each of these causes.
1. Blockage of the pore
So how does a pore get blocked in the first place? It all has to do with epithelial cells that line the central canal (follicle) within the pilosebaceous unit. Epithelial cells are formed at the basement membrane and move upward as they grow, mature, and die. As these cells are moving up to the surface of your skin, they become flatter and tougher and are eventually shed from your skin in the process known as desquamation. All in all, it takes for about 4 weeks for this process to complete.
If your skin is behaving like nature intended, this process works like a clock: new epithelial cells are born, mature, die, and eventually shed without causing any blockage. If your skin is out of whack, however, cell to cell connectors remain intact during the shedding process, which prevents dead cells from sloughing off and eventually results in a bunch of clogged pores. “Why, on earth, are my cell to cell connectors refusing to be nice to me?” you might wonder. There are at least two reasons. First is the slowdown in the rate of decomposition of the connectors. Second is the delay in programmed cell death. Both result in dead (or barely breathing) skin cells holding on to each other for dear life.
2. Excessive Production of Skin Oil
The second well-known cause of acne is overproduction of skin oil by the sebaceous glands. The primary reason why your sebaceous glands might be working overtime is that they are being stimulated by high level of male hormones androgens. In men, androgens are synthesized in the testicles, and in women they are made in the ovaries. The availability of this hormones in the blood stream is determined by a hormone produced in liver, known as sex hormone binding globuline (SHBG). There is an inverse correlation between levels of SHBG and androgens: the lower the levels of SHBG the higher the levels of androgens.
3. Bacterial Infection
Once a pilosebaceous unit gets nicely blocked by all those pesky dead skin cells that refuse to slough off, and your sebaceous gland starts pumping oil like crazy, an ideal environment has been created for bacteria colonization. The name of this bacteria is propionibacterium acnes, and usually it lives on your skin surface without causing any problems. Once they get locked up under your skin, however, they start a wild pool party, which your body does not condone. Immune system to the rescue!
4. Inflammation of the surrounding tissue
Certain substances found within the cell walls of the colonizing bacterium stimulate the immune system to produce localized pro-inflammatory hormones called cytokines. It is when your immune system gets revved up inside the pilosebaceous unit trying to kill all those little bastards under your skin that you end up with a bunch of red, fiery-hot, inflamed pimples. In fact, the more your immune system overreacts, the more cytokines it produces, so those extremely painful size of a cherry pimples you sometimes get are nothing more than a result of your immune system going completely bananas.
So here you have it, a sweet and short explanation of how all those whiteheads, blackheads, and zits are able to invade your face. This exact story is repeated on every acne-related website that tells you that the key to having a clear skin is to keep your pores open and bacteria at bay. What most of these websites seem to ignore, however, is the fact that our cell to cell connectors are not supposed to get stuck together, our sebaceous glands are not supposed to produce too much oil, and our immune system is not supposed to go crazy for no good reason. In other words, for many of us, answering the question “how” is not going to help much. What we need to know is why our skin refuses to behave. Once we have an answer to the “why” part, we can tweak the “how” part to work for each unique case.