Microdermabrasion and chemical peels are both methods of renewing skin cells and re-surfacing the skin. First let’s look at what skin is, exactly.
Structure of our skin
There are 3 layers to skin. The surface layer, called the epidermis, has 4 sub-layers and varies in thickness depending on where on the body it is, e.g. on our eyelids it’s very thin indeed (about 0.06 mm), and on the soles of our feet and palms of our hands, which can often be in contact with rough surfaces, it’s thicker (about 0.8 mm). The uppermost of the 4 sub-layers consists of dead cells that form a protective barrier for the living cells beneath. The lowest of the 4 is called the basal layer and here cells divide to create new daughter cells, which move upwards through the rest of the epidermis to the surface, and in this way, the skin continuously regenerates itself. Also in the basal layer, melanin is created, the pigment that sets our skin tone and responds to sunlight.
The middle layer, the dermis, is about 3-5 mm thick and is the main substance of our skin. It contains nerve endings, blood and lymph vessels (lymph is a clear fluid related to blood and circulates through the body in its own system), hair follicles, sebacious glands (which secrete a lubricating substance called sebum), and sweat glands. The capillaries (very tiny blood vessels) in this layer reach to within 0.2 mm of the skin surface and are important in healing skin injuries.
The subcutaneous tissue is the innermost layer, underneath the dermis and over the body tissues. It contains blood vessels and fat and is usually several millimeters thick. It’s absent in some areas, such as the eyelids. It helps to insulate the body and helps protect us if we fall or get hit by something.
Although we wash off some of the dead cells from the top epidermis layer, some remain and accumulate to create unevenness on the skin, roughness, and eventually an opaque look and loss of elasticity. Add to that some of the other skin problems we’re all potentially subject to, such as sun damage, fine lines and wrinkles, blackheads, whiteheads, age spots, and acne or other scars, and the stage is set for microdermabrasion.
How does it work? A hand-held tool projects tiny crystals onto the skin, gently scraping it clear, exfoliating it. The process is thorough because it includes mild suction as well as exfoliation, and stimulates the basal layer to create more new cells. Several treatments will be needed and can be spaced as closely as about 12 days apart. Each takes only about 15 minutes. There’s minimal discomfort afterwards and no recovery time required as the slight pink color will fade within a day or so.
The different kinds of chemical peels do essentially the same thing as microdermabrasion: remove the surface cells and stimulate the creation of more new ones. The difference is that they use chemicals of varying strengths instead of crystals.
There are 3 levels of strength. The mildest, the light peels, use alpha-hydroxy acids, typically glycolic acid which is made from sugar cane. (Over-the-counter peels use alpha-hydroxy acids at lower concentrations.) The acid is left on the face a short while and then neutralized or washed off. Exfoliation continues for several days and the new cells are in place after about 10 days. Treatments are done in a series of six or eight sessions, at intervals of two or three weeks, and penetrate the skin only lightly (only to the second layer of the epidermis, the spinous layer). If a scar is more deeply rooted, it will be only minimally affected.
The medium peels use trichloroacetic acid and take up to an hour. They cause a sense of burning for which your cosmetic surgeon may offer pain medication or sedation. After the peel has done its work (about 10 minutes), ice is used to neutralize it. Then the face is covered with an ointment or cream to help it stay moist and heal.
Medium peels penetrate more deeply (to the granular layer of the epidermis) than light peels, and are only done once every 2 years or so. Because they affect a deeper level of the epidermis, they can remove larger wrinkles and pre-cancerous lesions, and can be more effective on scars. But they still can’t remove a deep scar. And using a stronger acid, the medium peels burn the skin like sunburn, making it red for about a week.
Deep peels use phenol acid and take an hour or two for a full face treatment, with an anesthetic injected first. Sedation is sometimes used as well. After the peel has done its work, the face is rinsed with water and coated with petroleum jelly. For the next couple of days, under this coating, the skin forms a protective crust and then new skin with a sunburnt color, which fades to the patient’s normal color after a few more days.
Recovery time from these is 2 to 4 weeks. There’s some pain for the first few days and some swelling and the face can itch as it heals.
Deep peels are the most drastic, can remove coarse wrinkles and pre-cancerous lesions and bring results almost like a facelift, but they bring more risk too. They can cause uneven pigmentation and often the new skin stimulated this way can’t make melanin, pigment. So your skin will be not only lighter-colored, but unable to tan, which means you’ll need to always protect it from the sun. And even though it’s called a “deep peel” it can’t remove scars that are rooted below the epidermis. However, the effects can last as long as 10 years.
Read more articles about skin care.