What type of skin care should the cosmetician recommend to her clients to preserve the skin barrier?
The quotation "Never change a running system" also applies in the field of skin care, or in other words, the objective of skin care is to largely preserve the natural conditions of the skin - including the microflora. The composition of the preparations should be in line with this guideline. The preparations can contain barrier substances such as phytosterols (instead of the epidermal cholesterol), ceramides and long-chained fatty acids, sebum-related lipids such as squalane and triglycerides as well as moisture retaining components like amino acids, urea and glycerine. All the additional ingredients should be physiologically compatible and the dosage should be adapted to the individual skin condition.
How does the cosmetician know that the skin barrier is disturbed? What are the symptoms for a disturbed skin barrier?
The simplest case of a disturbed skin barrier is dry skin with more or less pronounced characteristic coarseness and scaliness at the surface as well as sensitivity to external influences. When measuring the skin, it will turn out that the skin moistness is low, the transepidermal water loss (TEWL) high and that there is a deficiency of superficial skin lipids (sebum). Beyond that, atopic skin and various cornification anomalies also cause disorders of the skin barrier.
Skin cleansing, peeling and conditioning - aren't they rather counterproductive measures?
Basically yes, on the other hand however hygiene also is rather important. With regard to an optimal skin condition this always will be a balancing act - particularly as far as skin cleansing is concerned. In any case, it is important to avoid excessive routines such as a daily deep pore cleansing and using too much and too many of the skin care products. Peelings are permitted however they should not be applied in short intervals over a long period.
What kind of substance groups/ingredients should be avoided in the skin care in this case?
In this context we should particularly think of cosmetic additives which do not serve for skin care but for other purposes such as for instance a long storage period. Belonging to this group are emulsifiers that cannot be degraded in the epidermis and hence cause increased wash out effects. Other substances to avoid are those that more or less seal the skin, impede the natural exchange and possibly lead to skin swellings. It is recommended to watch out for substances with well-known sensitizing and irritation potential - examples are fragrances and the preservatives listed in the annex of the German Cosmetic Regulation (Kosmetikverordnung - KVO).
Dr. Hans Lautenschläger