To Treat Dry Skin, Start by Understanding TEWL

Written by Lexli International

Transepidermal water loss, or TEWL, is an essential concept to understand when considering skin dryness. Although often overlooked, TEWL is one of the main reasons why moisturizing the skin regularly and with the right products is a crucial step in keeping skin healthy and hydrated.

TEWL occurs when the outermost layer of our skin, the epidermis, loses water to the surrounding air through evaporation. In fact, each day, the skin loses approximately one pint of water through TEWL. In a fairly humid environment, water evaporation from the skin is slow, and the body can readily replenish the water lost to the air. However, when water evaporates faster than the body can replace it, the skin becomes dehydrated, which can lead to irritated, rough and/or itchy skin that can crack and cause discomfort. Dry skin also tends to appear more aged, as fine lines and wrinkles are accentuated.

Optimizing the skin's moisture level is key to skin health and an important element in ensuring a youthful appearance. To achieve proper skin hydration and treat dry skin, internal and external factors must be considered.

We all know that meeting our water intake goals each day is beneficial to the body. Water aids in digestion, regulation of body temperature, transportation of nutrients and much more. And while a jury has long been out regarding its ability to directly benefit the skin, recent studies like this one have demonstrated that regular consumption of water does indeed lead to improvement in skin hydration. That's the internal side of the equation.

Ensuring that our skin is hydrated, however, doesn't prevent TEWL. If anything, the more water content in the skin, the greater the opportunity for TEWL to occur. Rather, from an external perspective, we must focus on slowing the rate of TEWL. To do that, we look to moisturizers.

There are three main categories of ingredients found in an effective moisturizer – humectants, occlusives and emollients. Humectants, such as propylene glycol, hyaluronic acid and sorbitol, are substances that naturally attract water. When used in humid conditions, humectants pull water from the environment to the skin. In dry environments, humectants often draw moisture from the deeper layer of skin – the dermis – to the epidermis. After humectants hydrate the skin, the water could easily evaporate. This is where occlusives come in. Occlusives, like petrolatum, caprylic/capric triglyceride and beeswax, are hydrophobic substances that act as a barrier through which water cannot pass. (With certain occlusives on the skin, the rate of TEWL can decrease by up to 98%!) Finally, emollients, including isopropyl palmitate, dimethicone and jojoba seed oil, are substances that help keep the skin smooth, flexible and lubricated. Many emollient constituents found naturally in the skin's oils, such as lipids and fatty acids, play important roles in the skin's architecture. In moisturizers, they improve the feel and comfort of the skin while greatly reducing TEWL.

TEWL is accelerated when the skin's barrier function is disrupted. Therefore, the amount of water that comes into contact with the skin should be limited. Water dilutes and washes away skin oils that act as natural occlusives to keep water in the epidermis. High water temperature can also increase TEWL, as it opens the skin's pores, allowing more moisture to evaporate. Shorter, cooler showers and baths are recommended for optimal skin health.

Avoid strong soaps. Heavy-duty soaps and cleansers with high pH levels can rapidly diminish the skin's supply of natural oils leaving moisture in the epidermis free to evaporate. Rather, turn to gentle cleansers or glycerin bars.
In dry climates or during dry seasons, use a humidifier in your home or office. TEWL is slower in humid environments.
Reapply lotions and moisturizers regularly to ensure that skin stays protected. This is especially important after washing hands or cleansing the face or body.

Login to post comments

Skin Care Connection

Latest Discussions

New This Month!

Mary McWilliams and 27 others have joined the group Acne Estheticians 3 days ago

Clear at Last: Acne Solutions that Actually Work
Clear at Last: Acne Solutions that Actually Work

Clear at Last: Acne Solutions that Actually WorkMonday, September 16, 201910:00 A.M. CSTPresented and sponsored by Repechage Acne – with close to 50 million people in the United States affected at some point in their lives – it’s an epidemic. And, one of the leading…

Browse-worthy Blogs

  • Got Energy? Feeding Your Inner Rainbow
    Got Energy? Feeding Your Inner Rainbow We think of energy as being physical – the boundless energy of children, nervous energy, and so on – but energy is actually fuel; your physical self depends on the energy from your subtle energy body. Your vitality, or lack thereof, comes from feeding yourself energetically – what I call feeding your inner rainbow. Here's how it works:
  • Target Wrinkles With The New Eminence Organics Marine Flower Peptide Collection
    Target Wrinkles With The New Eminence Organics Marine Flower Peptide Collection When targeting wrinkles and the appearance of aging, peptide technology is a collagen-boosting solution. What are peptides? According to Vogue magazine, they are “the building blocks of protein” that encourage the formation of protein in skin, like collagen. When peptides do their job of activating the production of collagen, skin looks younger and stronger with visibly fewer fine lines and wrinkles.
  • Are Ultraviolet Glass Bottles Worth the Price?
    Are Ultraviolet Glass Bottles Worth the Price? If you’re an avid skincare maker or consumer of small batch, artisan skincare products, I’m guessing that you’ve heard of ultraviolet glass bottles. This is a special type of glass that many natural formulators use to maintain the integrity of their products. Though it’s really violet in color, it appears black, and it’s become the preferred packaging for many of my students and colleagues. Ready for me to say something shocking about how Miron violet glass actually doesn’t work how…