Even dead skin cells can cause issues if their removal is hindered. Shedding dead skin cells is important for our skin’s health but too much exfoliating can damage the skin and lead to many problems. This article discusses desquamation and different types of exfoliants on the market.
Desquamation
Desquamation refers to the process of shedding dead skin cells from the outer layer of the epidermis. Our bodies naturally produce approximately 12g of dead skin cells a day. In healthy skin, desquamation takes approximately 3-4 weeks and our entire epidermis turns over in about 7-8 weeks. Desquamation works in tandem with keratinization which is the process where living keratinocytes move from the deepest layers of the epidermis towards the surface; both processes are critical to skin health. The rate at which desquamation occurs depends on the location of the body. For example, the forearm has a higher rate of desquamation versus the back versus the abdomen. The process of shedding of dead skin cells slows naturally with age but other factors like poor diet, stress, lack of sleep, environmental stressors and dehydration can also have an impact. Without proper desquamation, the skin barrier can become compromised and have a rough texture and dull appearance. There is still a lot of unknown information or confusing data related to desquamation. This is due to the challenge of accurately studying one variable while holding the others constant. Some skincare ingredients like retinoids, niacinamide and chemical exfoliants can assist with cell turn over.
Physical vs. Chemical
Our skin has a natural exfoliation process, but many things can disrupt this process. Luckily, there are products that can assist with exfoliation. Properly exfoliating our skin can help with clogged pores and acne and help our skin be more radiant, smooth and even.
Exfoliators are broken down into 2 main groups: physical and chemical. While physical exfoliators used to be popular, over time we’ve learned that this method is often too aggressive and rough for our face and neck. Physical exfoliators are abrasives (microdermabrasion, beads, sponges, cleansing brushes) that physically break up dead skin cells. It’s important to not use physical exfoliators if you’re breaking out. This will further harm or irritate the area and spread unwanted bacteria. Chemical exfoliators (serums, toners, masks) are either acids or enzymes that break down the bonds that hold cells together (proteins called corneodesmosomes). Chemical exfoliators can be used on more sensitive areas like the face and neck but also on more durable areas like armpits, legs, chest, etc. Some ingredients are sourced from fruits like pineapple (bromelain), papaya (papain) and kiwi (actinidin).
AHA, BHA, PHA
There are 3 different categories of chemical exfoliants: alpha hydroxy acids (AHA’s), beta hydroxy acids (BHA’s) and poly hydroxy acids (PHA’s). These are weak acids and proper selection depends on your skin type.
Alpha hydroxy acids or AHAs are water soluble and very popular. Glycolic acid is probably the most well-known out of this group and is considered the strongest as it is a smaller molecule and can penetrate deeper than other AHA’s. This is a benefit, but this can also be harmful as it can be more irritating to the skin. Lactic acid and mandelic acid are also AHAs and these options are becoming more popular in the industry. Lactic acid is great for brightening and mandelic acid is a good option for sensitive skin.
The most popular beta hydroxy acid or BHA is salicylic acid. This is great for people with oily skin as it’s slightly oil soluble. With these being oil soluble, they can penetrate deep into pores and help regulate sebum. While not nearly as common as salicylic acid, other BHA’s include beta hydroxybutanoic acid, tropic acid and trethocanic acid.
Lastly, poly hydroxy acids or PHA’s are newer compared to the others. They are similar to AHAs but are gentler. Some PHAs include gluconolactone and lactobionic acid. This group is good for people with dry or sensitive skin, or if you haven’t had luck with other chemical exfoliators.
There are a few items to keep in mind when using either a physical or chemical exfoliator. First, patch test any products before committing to a larger area. Exfoliate at night but not every night. This can potentially lead to irritation and disrupt your skin barrier. Adapt your exfoliating routine to your skin’s need and your climate. During the dryer months, your skin is more delicate and sensitive so it can be easy to over exfoliate. Always wear sunscreen the next morning and don’t try to convince yourself that pain or inflammation means it’s working; it’s possible it may just be irritating your skin.
