Physiological measurements of facial skin response under personal protective equipment

Medical device-related pressure ulcers (MDRPUs) were traditionally associated with skin-contacting medical devices applied to patients, eventually causing tissue damage. The coronavirus-2019 pandemic has brought a new variant of MDRPUs: facial skin irritation or damage associated with extended use of protective personal equipment (PPE), e.g. facemasks and respirators. In this context, we report here a comprehensive experimental evaluation including facial contact forces, skin temperatures and sub-epidermal moisture (SEM) measurements pre/post-PPE usage, to determine how these physiological parameters change under the effects of surgical facemasks and KN95 respirators and whether such potential changes can explain the commonly reported skin irritation or damage. We found that a surgical mask is potentially less irritating to facial skin than the KN95 respirator, as it applies lower forces and facilitates faster return of facial temperatures to their basal levels. Further, we demonstrated that use of dressing cuts for padding under a KN95 respirator considerably reduced localized forces and did not worsen the thermal and SEM readings at the skin-device contact sites. This study provides a basis for improvement of PPE designs, as it describes physiological measurement methodologies for quantitative comparisons of the effects of different PPE types on facial skin status.