What Causes Skin Acidity?

Skin acidity is primarily caused by the acid mantle, a thin, protective layer on the skin's surface. This mantle is formed by a mixture of sebum (oil) from sebaceous glands and sweat containing lactic and amino acids. The combination of these substances creates a slightly acidic pH level, typically around 5.5.

• Sebum: This oily substance produced by sebaceous glands helps to moisturize the skin and create a barrier against harmful substances.
• Sweat: Sweat contributes lactic and amino acids, further enhancing the skin's acidity.

This natural acidity is crucial for several reasons:

• Protection against bacteria and fungi: The slightly acidic environment inhibits the growth of many harmful microorganisms.
• Maintaining skin barrier function: The acid mantle helps to keep the skin hydrated and prevents moisture loss. A disrupted pH balance can compromise this barrier function, leading to dryness, irritation, and increased vulnerability to infections (Beeckman et al, 2015).
• Reducing inflammation: A balanced pH helps to prevent skin inflammation and irritation. An imbalance can lead to conditions like redness, itching, and acne.

Factors Affecting Skin pH

While the acid mantle naturally maintains skin acidity, several factors can influence its pH balance:

• Environmental factors: Harsh soaps, certain cleansers, and prolonged sun exposure can disrupt the skin's natural pH.
• Medical conditions: Certain skin conditions can alter the skin's pH.
• Age: Skin pH can change with age.
• Lifestyle factors: Diet and overall health can play a role.

The ideal skin pH is slightly acidic (around 5.5). Maintaining this balance is key to healthy skin. Disruptions to this balance, leading to a more alkaline pH, can manifest as dryness, redness, and irritation; conversely, an overly acidic pH may also lead to irritation.