Maintenance of skin pH is essential to the health and normal functioning of the skin. Where there are elevations in the skin pH, there are unfavorable outcomes such as impairments of a permeability barrier homeostasis, decreased skin integrity, cohesion, and increased susceptibility to microbial infections. Alterations in these skin functionalities play a known role in the pathogenesis and clinical manifestations of skin disease.
The acidic pH of the SC restricts colonization by pathogenic flora and encourages the persistence of normal microbial flora. Pertinently, newborn and elderly skin, intertriginous areas, and chronically inflamed skin display an increased skin pH and hence reduced resistance to pathogens. Higher pH (decreased acidity) and impaired buffering capacity predispose to infection and skin disease.
In Summary, increased skin pH can lead to abnormalities in the SC integrity/cohesion, permeability barrier homeostasis, pathogen resistance, and immune function. These abnormalities areattributable to the pH-mediated increase in the serine protease-mediated degradation of corneodesmosomes, defect in lipid processing, and decrease in antibacterial activity, respectively.
Now that we have a better understanding of the importance of maintaining tightly regulated skin pH, we can start to divulge the mechanisms behind skin acidification and buffering capacity.