Biometrology guidelines for the in vivo assessment of skin surface pH in nonclinical settings

Abstract

Skin surface pH plays an important role in the maintenance of skin barrier integrity and epidermal homeostasis. In workplace environments, myriad exposures may alter the skin surface pH and influence development of skin diseases. Unlike well-controlled clinical settings, workplaces and other nonclinical settings are more variable and present unique measurement challenges, making guidelines necessary for accurate determination of skin surface pH in these environments. The standard approach for the measurement of skin surface pH is the use of a glass planar electrode. Good measurement practices for nonclinical settings include: (1) minimizing the influences of relevant endogenous, exogenous, and environmental factors that affect measurements (e.g., anatomical position, hand washing, occlusion from use of protective garments such as gloves); (2) reporting pH measurement results on a relative basis, e.g., percent change rather than absolute values; and (3) capturing any events that may influence measurements. It is envisaged that these guidelines will promote better understanding of skin barrier integrity, particularly in occupational environments, and consequentially enable intercomparison of future study results