What really happens when you exfoliate skin?

By Prof. Des Fernandes, Dr Ernst Eiselen, and illustration by Shawna Akins-Wiesner and Jennifer Munro

.There is a serious and widespread misconception about the value of exfoliation. Most people believe the surface of the skin is composed of dead, useless cells that make the skin look dull, prevent the skin from “breathing” and can clog up the follicles. In reality these “dead” cells are the mature functional cells of the skin. They are there for a special purpose.

I believe we should avoid the harsh scrubbing exfoliants that seem to be found in most skin care ranges. They destroy too much of the horny layer and may even expose the stratum granulosum. Remember that the stratum corneum is only 2 hundredths of a millimetre thick so it is easily removed. A simple scratch on the skin surface may remove almost all the stratum corneum. It is bewildering to think of how fragile this layer is and yet the health of our skin is totally dependant on it.

Many therapists make the mistake of suggesting exfoliation to clients with normal skin with the belief that the client’s skin can be made more radiant and look fresh. We all know that immediately after exfoliation, the client will have a healthy pink glow with a lovely well-moisturised appearance and the client will be complimented on their skin. It looks great and indeed, some well-known skin care “experts” heartily endorse weekly exfoliation to maintain the best appearance.

The healthy pink moisturised cells that we see on the surface after exfoliation are actually cells that have not yet been properly prepared to encounter air and the environment. The client may be pleased, but the cells are shocked by this sudden exposure to the horrible environment. They cannot truly perform their function of protection because they themselves require protection! More water is lost through the skin and these cells cannot rapidly adapt to this new, harsh environment and after a few days the skin feels dry and the surface lacks lustre. Bearing in mind how good the skin looked immediately after the exfoliation, it seems that the obvious answer is to repeat the exfoliation and remove these offending dead cells! And so it goes on.

What else has happened? Well, the horny layer is thinner, so the physical protection has been removed and the photo-protective effects have been diminished: the skin is more vulnerable to damage. The waterproofing barrier has been compromised and so water can easily evaporate through the skin and as a result the deeper layers of the epidermis become de-hydrated. The chemical “messages” from the surface to the deeper layers of the epidermis beg for the cells to make a thicker horny layer to preserve the normal degree of hydration! This impaired horny layer also means that chemicals may get into the skin easier and so, for example, if the client decides to use a spray at home with an insecticide or some other noxious chemicals, then those harmful chemicals will get into the skin in greater concentrations. The same is true for any other environmental pollutant. Do you want to expose your client to that unseen danger?

 In order to understand exactly what you are doing and how it affects the skin , you need to know some details about the epidermis. The epidermis is the superficial layer of the skin that lies on the deeper dermis. The dermis contains fibroblasts, collagen and elastin fibres, nerves and blood vessels all lying in a jelly-like substance called the intercellular matrix. The epidermis is about 0.1 to 0.2 mm thick and comprises four distinct layers.

HOW CAN WE BEST ACHIEVE SAFE EXFOLIATION: 

I believe we should avoid the harsh scrubbing exfoliants that seem to be found in most skin care ranges. They destroy too much of the horny layer and may even expose the stratum granulosum. Remember that the stratum corneum is only 2 hundredths of a millimetre thick so it is easily removed. A simple scratch on the skin surface may remove almost all the stratum corneum. It is bewildering to think of how fragile this layer is and yet the health of our skin is totally dependant on it. 

I also believe that harsh peeling systems should be avoided except under special circumstances. If the therapist wants to do exfoliation by using a peeling system, then I believe simple “soft” chemical peels (e.g. low dose TCA, alpha or beta hydroxy acids etc) are superior to strong concentrations of acid or the harsh granular plant peels that mechanically abrade away the skin as well as peel it chemically. 

If the therapist does a manual exfoliation then they should make sure that the abrading granules are barely perceptible and the client always feels comfortable during and after the treatment. Steam or heated towels are also useful. 

The client may do the exfoliation themselves and again I would suggest the mildest abrading packs, or simple light alpha or beta-hydroxy creams or gels. One should stress to the client that this should not be done excessively, and also not forever and ever! The concomitant use of topical vitamin A helps to minimise the potential negative effects of over-exfoliation by promoting both the growth of the epidermis, as well as increasing the hydration of the skin. We have all seen the examples of chronic over-exfoliation by well-known therapists and clients using AHAs : their skin looks thin, lifeless and un-natural even though it might be smooth! 

Many therapists make the mistake of suggesting exfoliation to clients with normal skin with the belief that the client’s skin can be made more radiant and look fresh. We all know that immediately after exfoliation, the client will have a healthy pink glow with a lovely well-moisturised appearance and the client will be complimented on their skin. It looks great and indeed, some well-known skin care “experts” heartily endorse weekly exfoliation to maintain the best appearance. However, let’s look at reality. The client did not have an excessively thickened horny layer and so the exfoliation has removed some important mature functional cells with their surrounding lipid bi-layers. The healthy pink moisturised cells that we see on the surface after exfoliation are actually cells that have not yet been properly prepared to encounter air and the environment. The client may be pleased, but the cells are shocked by this sudden exposure to the horrible environment. They cannot truly perform their function of protection because they themselves require protection! More water is lost through the skin and these cells cannot rapidly adapt to this new, harsh environment and after a few days the skin feels dry and the surface lacks lustre. Bearing in mind how good the skin looked immediately after the exfoliation, it seems that the obvious answer is to repeat the exfoliation and remove these offending dead cells! And so it goes on. What else has happened? Well, the horny layer is thinner, so the physical protection has been removed and the photo-protective effects have been diminished: the skin is more vulnerable to damage. The waterproofing barrier has been compromised and so water can easily evaporate through the skin and as a result the deeper layers of the epidermis become de-hydrated. The chemical “messages” from the surface to the deeper layers of the epidermis beg for the cells to make a thicker horny layer to preserve the normal degree of hydration! This impaired horny layer also means that chemicals may get into the skin easier and so, for example, if the client decides to use a spray at home with an insecticide or some other noxious chemicals, then those harmful chemicals will get into the skin in greater concentrations. The same is true for any other environmental pollutant. Do you want to expose your client to that unseen danger?

The net result of repeated or over-exfoliation of healthy skin is, despite the healthy appearance, significant exposure to environmental toxins, free radicals, dehydration and interference with the normal physiology of the skin. Not only that, but the inevitable exposure to light makes the skin more likely to become photo-damaged. As skin care therapists, are we not supposed to make our clients skin healthier, well hydrated and more durable to exposure to light and environmental pollutants? I believe that the intelligent use of exfoliation is important but that exfoliation should be an uncommon way to treat skin and should not be part of the routine care of healthy well-nourished skin. A sensible skin care range actually makes exfoliation unnecessary and we should rather concentrate on treating our clients and ourselves in a scientific way to keep the horny layer as thick and smooth as it normally should be.