How Exfoliation Helps with Acne
Exfoliation Unclogs Pores by Removing Dead Skin Cells from the Skin Surface
The Essential Information
Healthy skin is constantly undergoing turnover. Old skin cells die and flake off, and new cells are born every day. In acne, this process becomes stalled, and old skin cells get stuck and accumulate, clogging pores. Exfoliation helps to restore normal turnover by removing dead skin cells. This not only helps to keep pores open but can improve the skin's appearance as well.
Glycolic acid is the most well-known ingredient in topical exfoliating products, and is available in strengths up to 10% over-the-counter.
Salicylic acid is also exfoliating, and helps reduce inflammation as well, and is available in strengths up to 2% over-the-counter.
Exfoliation on its own is unlikely to clear acne to the degree most people are looking for, but is a welcome addition to a proper anti-acne regimen.
Exfoliation refers to the removal of dead skin cells. Exfoliation happens naturally when dead skin cells fall off to be replaced by new skin cells in a constant process of turnover. However, in acne-prone skin, this process does not function properly, and products that exfoliate the skin can help.
Products that exfoliate the skin come in two types:
- Chemical exfoliants: These are acids that are applied topically to the skin. You can purchase over-the-counter products containing these chemicals, such as glycolic acid, in strengths up to 10%, or you can schedule a chemical peel at an esthetician's or doctor's office where stronger acids can be used. Chemical exfoliants work by helping to gently break down the connections between dead skin cells so they flake off easily. Chemical exfoliants can be beneficial for acne-prone skin by ensuring timely removal of dead skin cells, which would otherwise build up and clog skin pores. Some chemical exfoliants have additional benefits, like decreasing inflammation, which is a key part of acne. Verdict: Potentially beneficial.
- Physical exfoliants: These are objects like loofahs or substances like scrubs containing crystals or rough particles. Physical exfoliants work by roughly rubbing the skin surface, dislodging dead skin cells. Examples include loofahs, coffee scrubs, and sugar scrubs. While it seems to make common sense that physical exfoliants can help "scrub away acne," the opposite is true. Physical exfoliants are likely to do more harm than good to acne-prone skin by physically irritating the skin. It is well known that physical irritation can make acne worse. Verdict: Irritating. Avoid.
To understand exactly how chemical exfoliants can benefit acne-prone skin, let's take a look at the normal process of cell turnover in healthy skin and how that process goes wrong in acne.
The Circle of Life in Healthy Skin
The skin is the largest organ of the human body, and, as our external covering, it takes a beating--figuratively speaking--on a daily basis. The skin performs several important functions:
- Protecting the body from the external environment, including injuries, infections, harmful chemicals, and the sun's rays
- Regulating body temperature
- Preventing dehydration (excessive loss of water from the body)1-3
Because the skin is exposed to the elements, it needs to constantly renew itself in order to be able to do its job. This is why the top layer of the skin, called the epidermis, is constantly producing new skin cells while old cells die and flake off. This process occurs naturally and does not interfere with the skin's functioning.
Scientists estimate that it takes a human skin cell about 40-56 days to go through the full life cycle from birth to dying and flaking off.4 At any given time, your skin contains cells that were just born, cells that have died and are about to come off, as well as cells at various intermediate stages of the life cycle. Normally, the processes of cell birth and cell death are in balance, so that for every new skin cell that is born, another skin cell dies and is shed.
The circle of life in healthy skin: the full scoop
The upper, most superficial section of the skin is called the epidermis. This is the part of the skin that constantly renews itself.
The epidermis is subdivided into several layers. Skin cells begin their life cycle in the deepest layer, called the stratum basale. As they mature, they make their way up through the layers toward the most superficial layer, called the stratum corneum. Along the way, skin cells gradually lose their organelles (the internal parts that make cells work) and produce more and more keratin, a key in the skin. At the end of their life cycle, skin cells become dead shells filled with keratin.1-3
Living skin cells are connected to each other by strong, sticky connections called desmosomes. When skin cells die and the time comes for them to flake off, special enzymes in the skin break down these connections so that the dead skin cells can detach.1-3
How Skin Turnover Goes Wrong in Acne
There are many factors that contribute to the development of acne, but when it comes to the skin cell life cycle, there are two things that go wrong in acne-prone skin:
- Skin cells divide faster than normal. This means new cells are born more quickly than dead cells come off.
- Dead skin cells do not come off when they should. This means dead cells stay attached to the skin surface and to the inner lining of skin pores.
In other words, the balance between cell birth and cell death and removal is disrupted, so that too many cells are born and too few dead cells are shed. This results in an excess of skin cells. These extra cells end up clogging skin pores like a long cork stuck in a bottle.
Skin oil builds up in the clogged pore, creating the perfect conditions for acne bacteria to multiply. Once that happens, an inflammatory lesion, or what people usually call a pimple or a zit, that is red and sore, can erupt.5-9
How skin turnover goes wrong in acne: the full scoop
In acne-prone skin, the enzymes which are supposed to break down the desmosomes between dead skin cells do not function as well as in healthy skin. This is the reason why dead skin cells continue to hang around and clog pores instead of flaking off in a timely manner.
This, together with the fact that skin cells are dividing faster than normal, results in what scientists call "retention-proliferation hyperkeratosis," or, in plain English, too many skin cells.5-9
How Exfoliants Benefit Acne-prone Skin
Studies have shown that chemical exfoliants may help with acne and can be a useful add-on to topical acne treatments.
The most common chemical exfoliants are hydroxy acids like glycolic acid (an alpha hydroxy acid) or salicylic acid (a beta hydroxy acid). Hydroxy acids work by breaking down connections between dead skin cells so that they can flake off easily from the skin and from inside pores.10
When dead skin cells come off in a timely manner, skin pores can remain clear and skin oil can empty onto the skin surface instead of becoming trapped inside pores. In other words, by removing excess dead skin cells, hydroxy acids keep pores clean and prevent the formation of new comedones.10-13 Some scientists also suggest that higher concentrations of hydroxy acids can "unroof" pustules--in other words, unplug inflammatory acne lesions as well.11,12
The removal of dead skin cells also sends a signal to the skin to produce new cells. This helps to keep the circle of life chugging along in the skin, constantly getting rid of old cells and replacing them with new ones.
Exfoliation offers additional benefits. It:
- Makes the skin look smoother and clearer by removing dead skin cells. This can help make the skin appear more radiant and youthful.
- Makes the skin firmer and more elastic by stimulating the production of collagen, a skin protein that helps the skin look youthful.
- Helps hyperpigmentation (darkened spots) to fade faster by improving skin turnover.
- May increase the penetration of topical acne medications by removing excess dead cells from pores and from the skin surface.
- May improve skin hydration, helping to heal dry, sun-damaged skin and remove fine lines.10,13-15
In addition, some chemical exfoliants, like salicylic acid, can suppress inflammation, which is an integral part of acne.10,13
How effective are chemical exfoliants?
Chemical exfoliants can help with acne but are not recommended as a stand-alone treatment. In other words, just using a chemical exfoliant by itself is unlikely to dramatically clear acne.
Just how effective chemical exfoliants are depends on their concentration. The kinds of concentrations found in over-the-counter products act on superficial layers of the skin and can help "turbo-charge" other topical acne treatments. Chemical exfoliants found in higher-concentration chemical peels that are applied in a doctor's office or esthetician's office can work their way deeper into the skin and produce more dramatic results. However, one recent study found that even these professional chemical peels only produce results for mild-to-moderate facial acne and have little effect on severe acne.10
According to a 2011 article in the Journal of the European Academy of Dermatology and Venereology, "When used in mild-to-moderate facial acne, superficial peels reduce acne lesions."10
How exfoliants benefit acne-prone skin: the full scoop
As explained in a 2011 article in the Journal of the European Academy of Dermatology and Venereology, chemical exfoliants like hydroxy acids attack improve dead skin removal in two ways:
- They break down the desmosomes, or tight connections, between dead skin cells
- They increase the activity of enzymes in the skin that are supposed to naturally break down the desmosomes between dead skin cells10
The Bottom Line
The normal process of skin cell turnover is off-balance in acne-prone skin. Exfoliants can help by removing excess dead skin cells, unclogging skin pores, and helping to keep them clear. Some exfoliants have additional benefits for acne, like reducing inflammation.
- Denecker, G., Ovaere, P., Vandenabeele, P. & Declercq, W. Caspase-14 reveals its secrets. J Cell Biol 180, 451 - 458 (2008).
- Eckhart, L., Lippens, S., Tschachler, E. & Declercq, W. Cell death by cornification. Biochem Biophys Acta 1833, 3471 - 3480 (2013).
- Wong, D. J. & Chang, H. Y. Skin tissue engineering. Available from: https://www.ncbi.nlm.nih.gov/books/NBK27029/
- Koster, M. I. Making an epidermis. Ann N Y Acad Sci 1170, 7 - 10 (2009).
- Webster, G. F. & Rawlings, A. V. Acne and Its Therapy. (Informa Healthcare USA, Inc., 2007).
- Moradi T. S. et al. Acne vulgaris. Nat Rev Dis Primers 1, 15029 (2015).
- Degitz, K., Placzek, M., Borelli, C. & Plewig, G. Pathophysiology of acne. J Dtsch Dermatol Ges 5, 316 - 323 (2007).
- Tosti, A., Grimes, P. E. & De Padova, M. P. (Eds.). Color Atlas of Chemical Peels. (Springer, 2012).
- Available from: https://www.pharmaceutical-journal.com/news-and-analysis/features/innovation-in-acne-treatment-is-long-overdue-but-the-treatment-pipeline-looks-promising/20203702.article?firstPass=false
- Dréno, B. et al. Expert opinion: efficacy of superficial chemical peels in active acne management--what can we learn from the literature today? Evidence-based recommendations. J Eur Acad Dermatol Venereol 25, 695 - 704 (2011).
- Araviiskaia, E. & Dréno, B. The role of topical dermocosmetics in acne vulgaris. J Eur Acad Dermatol Venereol 30, 926 - 935 (2016).
- Tung, R. C., Bergfeld, W. F., Vidimos, A. T. & Remzi, B. K. Alpha-Hydroxy acid-based cosmetic procedures. Guidelines for patient management. Am J Clin Dermatol 1, 81 - 88 (2000).
- Kempiak, S. J. & Uebelhoer, N. Superficial chemical peels and microdermabrasion for acne vulgaris. Semin Cutan Med Surg 27, 212 - 220 (2008).
- Rodan, K., Fields, K., Majewski, G. & Falla, T. Skincare Bootcamp: The Evolving Role of Skincare. Plast Reconstr Surg Glob Open 4, e1152 (2016).
- DiNardo, J. C., Grove, G. L. & Moy, L. S. Clinical and histological effects of glycolic acid at different concentrations and pH levels. Dermatol Surg 22, 421 - 424 (1996).
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