You’ll have been told in school that your skin isn’t just body-covering, it’s an organ. That’s true. It does a lot of things, it’s surprisingly complicated, and it’s heavy – like 20 pounds, or 9 kilos.
You’ll also have been told, by advertisers, that you need to ‘exfoliate’ periodically, scrub off dead cells that accumulate on your skin’s surface. That’s not particularly true. They’ll fall off anyway. If they don’t, it’s because of skin trauma or some pathology like eczema. That leathery stacking-up of cells is called ‘lichenification’, and you’d know if you had it, and cosmetic-counter remedies wouldn’t be enough to treat it.
Still, some people swear by exfoliation, and say it makes their skin feel fresh and glowing. They may not be entirely wrong. For some people it does seem to have a nice finishing effect, and it feels good.
But skin type and skin condition vary, and ‘exfoliation’ can mean more than one thing.
Let’s talk about cells, and then let’s talk about scrubbing.
Most of your skin you don’t see. There’s a deep layer of connective tissue, mostly collagen-rich ‘dermis’, which gives the skin its supportive strength. In animal skin, this is what makes leather. On top of this layer is an ‘epidermis’ layer. (Epi-means ‘upon’ in Greek.)
That epidermis is what most of think of as our skin. It exists in layers of its own, of differentiated forms of tough ‘keratinocyte’ cells, so called because they fill up with proteins called keratins. (This is the stuff of hair, nails, hooves, and horns.)
Keratinocytes start at the bottom of the epidermis, as ‘basal’ cells. Some of them slip gradually out of that basal layer, and migrate slowly upwards, flattening out, and beginning to attach to each other. We start calling them ‘squamous’ cells at this point. They begin losing their living interiors as they migrate, and they become interlocked plates, eventually, a sealed and waterproof ‘cornified’ layer of cells. Finally, above this, there is an outermost layer of hexagonal stacks of completely dead, completely keratinized ‘squames’. It’s these that loosen and flake off.
They don’t need to be scrubbed off. They shed constantly. An unappetising fact you may not know is that most of the dust in your house is comprised of these squames. That’s how abundant they are. And making squames is a quick process, biologically speaking. The skin cell replacement cycle, from basal to flake-off, takes about a month. (It’s faster in children, and slower in the elderly.) That means your skin will replace itself completely about a thousand times in your life.
That’s a lot of cells. It’s a tempting idea to exfoliate like mad.
The thing is, your skin might be sensitive. Your skin might be unusually dry. Your skin might be unusually oily. Not everybody’s skin is the same. Exfoliated too much, or too hard, for no reason, your skin could lose some of its natural protective properties. You could end up with skin irritation. You could encourage acne breakouts. That’s not at all unusual.
At-home exfoliation either means mechanical scrubbing, or it means chemical treatment, typically with lipohydroxy acid, a derivative of salicylic acid and therefore a cousin of aspirin, that’s supposed to soften cells and get them to fall away. It does, and it stimulates glycosaminoglycans, collagen, and elastin, which helps bulk up the dermis, and it may also help keep acne at bay. But it can irritate, too. Other people use retinoid creams, or products containing benzoyl peroxide. These too, particularly if they’re used too often, cause some people’s skin to inflame, or even peel. They’re not necessarily good. If you want to try an exfoliant, it’s worth having a conversation with your dermatologist about it first.
If you’re going to scrub, be gentle. Also, use lukewarm water, not hot, as some people do, thinking it’ll hasten the departure of those dreadful squames. Then follow up with a moisturizer. And finally, monitor what happens. Figure out what exfoliating schedule actually suits your particular skin.
Don’t overdo, in other words. Healthy skin doesn’t need very much help to stay healthy. Trying to scrub it into super-health may actually, in the end, do something like the opposite.
Questions about your skin? Ask our dermatologists online for $35.