Skin pH: From Basic Science to Basic Skin Care – PDF Doc
The “acid mantle” is a topic not only of historical interest, but also of clinical significance and has recently been linked to vital stratum corneum function. Despite compelling basic science evidence placing skin pH as a key factor in barrier homeostasis, stratum corneum integrity, and antimicrobial defense, application of the acid mantle concept in clinical care is lacking. We review recent basic science investigations into skin pH, discuss skin disorders characterized by aberrant pH, and finally discuss practical application for preservation of the acid mantle. Recognizing factors that alter skin pH and selecting products that preserve the acid mantle is of prime importance in treating dermatologic patients. Key words: skin pH; acid mantle; stratum corneum; barrier homeostasis; serine protease; atopic dermatitis; acne; intertrigo; diaper dermatitis; syndets.
Skin pH is normally acidic, ranging in pH values of 4–6, while the body’s internal environment maintains a near-neutral pH (7–9). This creates a steep pH gradient of 2–3 units between the SC and underlying epidermis and dermis. The physiologic role of an acidic skin surface, historically was thought to be a defense mechanism against invading organisms. More recently, it has been demonstrated that several key enzymes involved in the synthesis and maintenance of a competent skin barrier are largely impacted by pH. Hence, a broader view of the importance of pH in relation to function and integrity of the skin is emerging.