Back to Part 3
The Evolutionof a Pimple
the formation of a pimple
Classifying your acne
Ah, the pimple. It’s the bane of many a school picture and wedding day. Pimples help keep photo re-touchers in business. But for many people, pimples aren’t simple nuisances that pop up at inopportune times. Instead, they’re a daily reminder that seemingly uncontrollable forces are at work in the skin. In this chapter, I outline the events that are required to make acne lesions. (A lesion is dermatologist lingo for any abnormality or mark of the skin. A pimple is a lesion. A blackhead is a lesion. Your nose isn’t a lesion, unless you have two of them.) I take you through many of the conditions necessary for a lesion to form and evolve: blocked hair follicles, overworked oil glands, and bacteria. Then I help you categorize your acne in order to understand when and why different treatments are used on the various types.
The High Price of Oil
Acne lesions originate and mature in the hair follicle, the epicentre of our acne story. (To get a visual of what a normal, healthy follicle doing its job looks like, take a peek at Figure 3-1.) Ultimately, in order for acne to develop, a follicle must be blocked. A blocked follicle isn’t the only condition necessary for acne to form (I detail the others in sections that follow and later parts), but it’s a big one. So, to talk about the roots of acne, you need to go directly to the hair follicle. Technically, the hair follicle and sebaceous gland are called the pilosebaceous unit (PSU). For simplicity sake, I just refer to the whole thing as the “follicle” or “hair follicle”
The hair follicle (actually the PSU) is made up of three components:
Sebaceous gland: This gland resembles a cluster of grapes and produces and pumps out a beneficial oily substance called sebum (pronounced see-bum) that coats and conditions the hair and skin. The oily sebum is composed of a rich blend of different lipids (fatty chemicals). Sebum rises to the surface of your epidermis to keep your skin lubricated and protected. It also helps makes your skin waterproof. Plus, sebum helps carry dead skin cells out of the hair follicle and to the exterior skin so that the body can get rid of them. In people with acne, there is an excessive production of sebum. Along with its producer, the sebaceous gland, its fellow cast member, the hair follicle, and its director testosterone (an important hormone), sebum plays much more than a bit part in the acne story.
Sebaceous duct: This tiny tube steers the sebum (and the dead skin cells it carries) from the sebaceous gland into the hair canal, the part of the follicle through which sebum travels onto the hairs before it is carried out to the exterior of your skin.
Hair: I’m talking about the actual hair that sprouts out of your pores (follicular orifices, or the holes in your skin that your hair grows out of). Hairs are sometimes called strands or hair shafts. Hairs are found all over our bodies; well, almost all over. There’s no hair on your palms, I hope. Hairs help carry sebum to our skin.
Pumping with hormones
Hormones play a central role in the acne drama. Hormones are the body’s chemical messengers. Without hormones, you wouldn’t have acne, but you’d be in pretty bad shape, because hormones control just about every bodily function, from regulating your metabolism to ensuring that you can mature and have children. In both males and females, a particular group of hormones, called androgens, are primarily associated with the formation of acne. The term androgen is a general term for hormones that have more masculinising features. Androgens are responsible for the development of secondary sex characteristics in males (facial hair, increased muscle mass, the ability to reproduce, and so on). The androgen testosterone is the main male hormone. However, if you’re female, you have androgens too, but they’re produced in smaller quantities and are much weaker than in your male counterparts. Estrogen and progesterone are the primary female hormones that control menstrual cycles and regulate pregnancy. Both of these hormones can have an effect on acne as well — albeit less than androgens — by their periodic monthly fluctuations. (I talk more about these hormones in later parts) The androgenic hormones help us regulate how much sebum (the healthy oil I describe in the preceding section) our sebaceous glands produce. People who get acne aren’t producing any more of these androgens than anyone else; it’s just that their sebaceous glands are very sensitive to the hormone’s message to increase production. The glands respond by pumping out excessive amounts of sebum. Your face, chest, and back contain the highest concentrations of sebaceous glands; that’s why you’re more likely to have acne on these areas. Adolescence is generally the worst time for acne because androgens
are increasing steadily during the teen years, and they signal your sebaceous glands to get larger and to generate more sebum, As adolescence ends, the amount of androgen secretion diminishes and acne tends to disappear for most teens by age 18 or 19. But for various reasons that I discuss later, some women (and much less commonly, men) retain a heightened sensitivity to their androgens and continue to have acne beyond adolescence. Some women even get acne for the first time as adults.
Clogging your pores and narrowing the hair canal
Every day, millions of skin cells die off. You continually make new skin cells and get rid of dead ones. Your body has ingenious ways of getting rid of dead cells. In the case of your skin, sebum carries the dead skin cells to the outside of the body where they flake off. Sometimes, though, as sebum ferries dead cells from the inside of your hair follicle along the oily sebaceous ducts and out through the hair canal, the exit route of the follicle is blocked by the excess oil. This blockage causes the opening of your hair canal to narrow, and your pores, the tiny openings in your skin that serve as exits for your hairs, get clogged. The exit of oil is also often impeded by a process called abnormal follicular keratinization. That’s a fancy way of saying that instead of flaking off with the sebum when they reach the skin’s surface as they normally do. The dead skin cells and keratin clump together with the oil to further clog the sebaceous ducts and hair canals. Acne is not caused by forgetting to wash the oil off, or even by eating loads of greasy French fries and junk food. It’s not the oil in your tummy or on your skin; it’s the oil in your skin.
Blackheads and whiteheads
The trapped sebum, cells, and keratin form a very sticky mixture — a real traffic jam that blocks the exit route. This plugs acts just like a cork in a bottle, locking in all that stuff inside with nowhere to go, so that it can’t exit onto the surface of the skin. The plug is called a microcomedo (pronouncedmy-kro-cahm-e-doe). You can’t see a microcomedo with the nakedeye; it’s too small. Over time, the increasing amount of trappedsebum builds up a lot of pressure and the hair follicle blows up like a balloon and becomes a visible comedo (pronounced cahm-e-doe;the plural of comedo is comedones).There are the two types of comedones
Blackheads: If the comedo enlarges and pops out through the surface of the skin, the tip looks dark and it’s called a blackhead. The dark color is not due to dirt; it’s the result of a build up of melanin, a dark pigment in the skin that turns black when exposed to oxygen in the air. Blackheads are also known as open comedones.
Whiteheads: If the comedo stays below the surface of the skin, it’s light in colour and looks like a small whitish bump; it’s called a whitehead. Whiteheads are also called closed comedones. Comedogenesis is the medical term for the process that forms whitehead and blackheads.