The Basics of Skin Care
Opinions are divided over the term cosmetic. While for some, beauty care is a part of personal well-being, many cosmetic dermatologists are more sceptical.
Dermatology is defined as the diagnosis and treatment of skin and venereal diseases. It also encompasses, along with parts of aesthetic and cosmetic surgery, skin pharmacology.
In earlier times no clear distinction was made between medicine and cosmetics. Hippocrates, the "father of medicine", left behind an extensive collection of cosmetic formulas. Galen of Pergamon, the father of pharmaceutical formulation, studied besides anatomy, hygiene, pathology and pharmacy also the art of formulating cosmetic preparations. In the late Middle Ages, however, cosmetics were separated from medicine. At the beginning of the 14th century, Henri de Mondeville wrote a text book on surgery in which he drew a clear distinction between the pathological and cosmetic aspects of treatment.
Since then, dermatology has dealt with the problems of pathological skin alterations requiring medical treatments and cosmetics with questions of skin beauty. The unity of health and beauty was sacrificed for the benefit of purely scientific considerations. Thus science stopped taking into account the more general aspects of well-being and cosmetics forgot the medical aspects.
Modern medical skin care
Medical skin care results from the restoration of that unity of medicine and cosmetics that was lost in the Middle Ages. Body hygiene and body care are of fundamental importance to the maintenance of good health, and play a vital role in disease prevention and adjuvant care. In recent years several expert bodies have been established to develop concepts for cosmetic dermatology.
The aims of medical skin care
The primary aim of medical skin care is to restore and maintain eudermia. Eudermia (i) is a state where physiological skin conditions prevail. Healthy skin is for the most part the result of a balance of moisture and lipids, along with a physiological pH (i) of the skin's surface, which determines the resident skin flora.
In the course of medical skin care, various active substances are applied to the skin to reinforce its protective functions and correct imbalances. Thus, skincare products can protect the skin from damaging environmental influences (i) such as dryness and the cold. In addition, application of moisturizing factors and lipids restores the skin condition and so prevents the development of disease. In the case of certain dermatological diseases, it can support the appropriate medical therapy as a complementary care program. While skin care can counteract the damaging effects of exogenous environmental influences (i), endogenous factors such as biological skin ageing cannot be influenced.
Moisture supply - hydration, moisturization
Introducing water into the horny layer - hydration - is very easy. The water phase of a skincare emulsion can supply the skin with an abundance of moisture in a very short time. However, the desired skin-moisturizing effect does not last for very long: The skin quickly loses moisture by evaporation. A longer-lasting hydration of the skin can be achieved with the help of other components: a supply of hygroscopic substances known as moisturizers (i) and/or an improvement of the moisture retaining capacity by occlusion.
Lipid supply - sebaceous lipids, barrier lipids
The lipid phase of a skincare emulsion restores to the skin the lipids it needs. Two types of lipids are especially important:
- Sebaceous lipids: constituents of sebum. They form a more or less occlusive film on the skin. The addition of sebaceous lipids to dry, oil-deficient skin restores the normal skin condition.
- Barrier lipids: primarily ceramides, cholesterol and free fatty acids, especially linoleic acid. They are found among the lipids of the stratum corneum. The horny layer's permeability barrier (i) is mostly determined by the content of these epidermal lipids. It can be improved by topical application of skin-related lipids
Ways to increase skin hydration:
- Natural Moisturizing Factors (NMF): The skin’s own substances that are able to bind water in the horny layer. They are derived from sweat, sebum and the cornification process including urea (i), lactic acid and amino acids.
- Vitamins: For example, dexpanthenol (provitamin B5) and vitamin E. Apart from typical properties exhibited in biochemical processes, they have a pronounced ability to bind water.
- Hyaluronic acid: As a mucopolysaccharide an important constituent of connective tissue. It has a very good moisture-binding capacity.
- Alpha-hydroxy acids (AHA’s): Lactic and citric acid (NMF) as well as malic acid, tartaric and glycolic acid
- Occlusion: Even an emulsion containing no active ingredients can influence the moisture content of the skin. For example, lipid bases made of paraffin hydrocarbons have a strong hydrating effect due to occlusion of the skin surface, leading to additional accumulation of water in the horny layer.