Transepidermal water loss (TEWL) refers to the amount of water that evaporates from the skin’s surface due to various factors, including environmental conditions, skin barrier function, and individual hydration levels.
TEWL is a natural process that occurs as the skin attempts to maintain its hydration levels and temperature. However, excessive TEWL can lead to skin dehydration, impaired barrier function, and increased sensitivity, resulting in skin that appears dull, dry, and prone to irritation or inflammation. By addressing TEWL and its contributing factors, beauty professionals can help clients maintain healthy, hydrated skin.
TEWL is crucial for maintaining skin’s optimum balance and barrier function. Low levels of TEWL indicate that the skin is effectively retaining moisture, resulting in a healthy, well-hydrated, and youthful appearance. However, increased or excessive TEWL can lead to dryness, irritation, and impaired skin barrier function, which can exacerbate conditions such as eczema, psoriasis, and atopic dermatitis.
Several factors can influence TEWL, including:
- Environmental factors: Temperature, humidity, and exposure to wind or air conditioning can affect the rate of TEWL. Low humidity environments, such as dry or cold climates, can exacerbate TEWL, leading to increased skin dehydration.
- Skin barrier function: The skin’s barrier function plays a crucial role in preventing excessive TEWL. A compromised skin barrier, often caused by factors such as over-exfoliation, harsh cleansers, or skin conditions like eczema, can result in increased TEWL.
- Individual factors: Age, genetics, and overall skin health can influence TEWL. As the skin ages, it tends to lose moisture more easily, resulting in higher TEWL rates.
- Medical conditions: Certain medical conditions, such as diabetes and kidney disease, can increase TEWL.
- Skin care products: Harsh soaps, detergents, and alcohol-based products can all increase TEWL.
The skincare market is continuously evolving, and as a result, there has been a significant rise in demand for products and treatments that maintain and improve skin hydration levels. Such products include hyaluronic acid (a humectant that attracts water to the skin), ceramides (lipids that help to protect the skin’s natural barrier), and occlusive moisturizers (which form a protective film on the skin’s surface to prevent TEWL).