Acid mantle

With the concept of the acid mantle of the relationship between the measured weakly acidic pH of the epidermis and the bactericidal effect of the secretions of the skin glands was formed (in particular welding and fatty acids ) is explained. The measured pH 4-7 in humans is clearly protect like a cloak against pathogens.

History

The term " acid mantle of the skin," the later acid mantle ( hydro-lipid coat) was traced back to the work of the physician Marchionini, who together with his teacher H. Schade 1928 an article in the Klinische Wochenschrift, entitled: The acid mantle of the skin published (after glass chain measurements). measurements of the hydrogen ion concentration, they found that the skin surface is covered by a layer of acid. however, this finding was not entirely new. early as 1892 E. Heuss had reached that conclusion. Marchionini but first introduced the relationship between measured acid pH values ​​and bacterial colonization of the skin here. Emphasis was, " that the body zoom pulls the same agent at three locations as diverse as stomach, vagina, and skin to bacterial defense ".

Criticism

In vitro studies revealed later cast serious doubt on whether the measured pH alone contributes to defense against bacteria. Pillsbury and Rebell reasonably equally good growth of Staphylococcus aureus at pH 5, 6 and 7 Further investigations came to the conclusion that the medium pH not affect the number of skin bacteria, but rather its enzymatic activity. Crucial for the antimicrobial activity are also the fatty acids present in sweat, the know their strongest efficacy at pH 5. It finally sat down by the realization that in solvent extracts of human skin mainly bactericidal lipids and peptides (such as beta -defensin ) are that are able to kill hemolytic streptococci and other gram-positive bacteria.

Later, the concept of the acid mantle was mainly taken up by the advertising industry and markets. Synthetic detergents should the acid mantle better "protect" (or restore ) than the alkaline soaps. Many components of the acid mantle as lactic acid, uric acid or the fatty acids are washed away, however because of their good solubility in water without the aid of detergents with the water. It spread quickly of the opinion that can be "destroyed" in to intense and frequent cleansing of the skin with (too hot ) water and detergent such as washing soap of the acid mantle of the skin and the skin flora gets out of balance. However, scientific studies refute this widespread opinion. A longer-lasting effect on the pH of the skin surface could not be achieved even with prolonged use of soap, because the skin surface pH shift regresses in healthy skin after washing within a few hours.