“Normal” TEWL‐how can it be defined? A systematic review

Abstract

An optimal amount of water, especially in the stratum corneum, is essential for maintaining normal functioning, healthy skin. 1 Therefore, the amount of water from the skin is carefully regulated, in part through trans-epidermal water loss. 1 Trans-epidermal water loss (TEWL) is an objective measurement of the amount of water passively evaporating from a designated area of stratum corneum in a fixed amount of time due to the water vapour pressure gradient on either side of the skin. It has historically been used as a measure of barrier water function and skin integrity in healthy individuals. 2 Advantages of using a non-invasive marker of skin integrity such as TEWL include a lack of skin barrier destruction, and the potential for early detection of subclinical effects. 3 Elevated TEWL values may reflect barrier dysfunction in diseases such as atopic dermatitis and psoriasis. 4,5 Oppositely, decreased TEWL values reflect an intact or recovered dermal barrier. 5 Thus, TEWL values are typically measured for in vitro permeation testing (IVPT) to reflect a healthy skin sample, and regulatory agencies such as the Food and Drug Administration (FDA) and European Group for Efficacy

Effect of the Hypoxic Chamber Training Series on Skin Characteristics of Overweight and Obese Women

“…When discussing the results on TEWL, it should be pointed out that once again confirmation was obtained that TEWL is positively correlated with BM, although more often authors present results based on BMI [30]. The higher the body weight, the higher the TEWL value.…”

Grand challenges in genetics and epidemiology of allergic diseases: from genome to exposome and back

“…Even in the cases of some allergic diseases that can (apparently) be defined more clearly as compared to asthma, specific objective measurements that can be used to better characterize the disease, such as trans-epidermal water loss (TEWL) in atopic dermatitis, may be not entirely reliable. Green et al ( 30 ) studied various factors that could affect TEWL values and concluded that at least 12 were not well controlled in experimental settings, which led them to conclude that the definition of normal TEWL is probably problematic. However, even when external factors can be fully controlled, as may be the case with TEWL, genetic factors can alter the response to drugs used in the process of definition of the disease.…”

The effect of adjuvant radiotherapy on skin biophysical properties in patients with breast cancer at risk for breast lymphedema: A prospective study

“…Yet, potential changes in epidermal barrier function in the case of preclinical lymphedema with the effect of RT are not well known. Transepidermal water loss (TEWL) has been known as a valid and objective measurement that directly assesses the amount of evaporated water regarding the epidermal function of the skin (Green et al, 2022; Gupta et al, 2007; Steiner et al, 2011; Winker et al, 2009 ) . Lower TEWL rates indicate better SBF or vice versa (Green et al, 2022; Jansen van Rensburg et al, 2019).…”