Function of the skin flora
Skin flora is the term used to describe the countless microorganisms that colonize the skin from the outside. These include a wide variety of bacteria, spores and fungi that are permanently or only temporarily settled there. The bacteria colonize the skin very densely and are an extremely important part of the healthy flora.
In a healthy skin flora about 1000 germs/cm2 can be found. They protect the body from pathogens as long as the skin is intact and forms a barrier. Individual body regions are home to different types of microorganisms.
Thus, hairy parts of the body have a different flora than the palms of the hands, for example. Bacteria and fungi look for the part of the body where their survival conditions are best. Factors that influence the skin flora are mainly moisture content, pH value, fat content and the amount of cornea, furthermore, genetic factors, age, sex or surrounding climatic conditions play a role.
For example, in rather fat-rich areas of the body, such as the nose or shoulders, mainly so-called propionibacteria and corynebacteria grow, as they can process the fats well. In places of the cornea, such as the sole of the foot, numerous fungi grow instead, which can feed on the keratin of the skin. If the moisture of a body part increases, the number of germs also increases.
Some microorganisms of the skin flora can also potentially be pathogenic and cause inflammation. However, if they are in balance, the barrier function of the skin is maintained and if the person’s immune system is functioning adequately, they do not pose a risk of disease. Due to their dense colonization, they even make it difficult for pathogenic germs to colonize the skin.
If the balance of the microorganisms is disturbed by internal or external influences, diseases caused by pathogenic germs can occur. Internal influences include, for example, a change in the hormone balance during puberty. This allows pathogenic organisms to attack and inflame the hair follicle, which leads to the typical picture of acne in adolescents. An external influence to disturb the skin flora can be excessive hand hygiene. By eliminating the healthy skin flora, an increased number of disease-causing bacteria can therefore colonize the skin.
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