Skin Surface pH in Acne Vulgaris

As the largest organ of the human body, our skin acts as a barrier to protect our bodies from any external threats. When proper skin barrier function is compromised, our skin is susceptible to infection and chronic inflammatory skin conditions such as psoriasis, atopic dermatitis (commonly known as eczema), and acne vulgaris (commonly known as acne). Researchers have found that alterations in the pH level of the stratum corneum, the outermost layer of skin, can negatively impact skin barrier function and therefore may play a role in the development of acne.^[1]

The pH scale describes the acid-base ratio of a substance ranging from 0 (the most acidic) to 14 (the most basic). Normal skin pH falls within the pH range of 4-6, which is acidic. In this study, skin pH was measured in 400 individuals – half of the individuals had acne while the other half had normal skin. 

The researchers discovered that a majority of the subjects with normal skin had normal skin pH (average of 5.09) while a majority of the individuals in the acne group had higher pH (average of 6.35). These results demonstrate a clear association between alterations in skin pH and acne. As such, treatments restoring normal skin pH may be effective for acne in addition to the many topical and systemic treatments already available. 

Several factors that affect skin pH, such as age, ethnic origin, and sex, are out of our control. However, diet, facial cleansers, and topical products can certainly affect skin pH as well and can be easily modified. Since acne is caused by many different factors, it can be frustrating for patients and practitioners to find the most effective treatment. Being more mindful of the pH on the skin may be helpful in controlling acne.