No abstract

Transepidermal water loss (TEWL) is regarded as one of the most important parameters for characterizing skin barrier function but an agreed upon definition of what a "normal" TEWL is does not exist. In order to determine generalizable TEWL values for healthy adults, a systematic review and meta-analysis was conducted. The databases MEDLINE and EMBASE and publication lists were screened. After full-text appraisal of 398 studies, 231 studies were excluded due to unclear or insufficient reporting. 167 studies providing data about 50 skin areas were included in the final data synthesis. Pooled sample sizes ranged from n = 5 for the left cheek and the left lower back to a maximum of n = 2,838 for the right midvolar forearm area. The lowest TEWL of 2.3 (95 % CI 1.9-2.7) g/m(2)/h was calculated for the breast skin, the highest TEWL of 44.0 (39.8-48.2) g/m(2)/h for the axilla. TEWL in individuals being 65 years and above was consistently lower compared to the group of 18- to 64-year-old individuals. The quality of reporting TEWL in humans should be increased in future studies.

Ageing is associated with structural and functional changes of the skin that result in increased vulnerability. The aim of this systematic review is to synthesize empirical evidence about the efficacy and effectiveness of basic skin care interventions for maintaining skin integrity in the aged. The databases Medline, EMBASE, CINAHL (1990-2012), Scopus, SCI (February 2013) and reference lists were searched. Inclusion criteria were primary intervention studies using skin care products in physiologically aged skin (lower age limit 50 years). Study and sample characteristics, interventions and outcomes were extracted. The methodological quality was assessed and a level of evidence was assigned. From 1535 screened articles 188 were read in full text. From these, 33 articles were included reporting results on treating dry skin conditions, and preventing incontinence-associated dermatitis and superficial ulcerations. Most studies had lower levels of evidence of 3 or 4. Skin-cleansing products containing syndets or amphoteric surfactants compared with standard soap and water washing improved skin dryness and demonstrated skin-protecting effects. Moisturizers containing humectants consistently showed statistically significant improvements in skin dryness. Skin barrier products containing occlusives reduced the occurrence of skin injuries compared with standard or no treatment. Owing to methodological limitations the current evidence base for basic skin care in the aged is weak. Using low-irritating cleansing products and humectant- or occlusive-containing moisturizers seems to be the best strategy for maintaining the skin barrier function and integrity. We know little about the effects of cleansing regimens and about the benefits of moisturizers when compared with each other.