Parakeratotic corneocytes play a unique role in human skin wound healing

Upon revisiting of our large library of archived human skin wound specimens, we observed that stratum lucidum interfollicular parakeratotic corneocytes appear to take an active role in epidermal wound healing by expanding, migrating and bifurcating to interact directly with and secure the wound scab in place. Our observations are based on the morphologic analysis of 240 acute, normal, full-thickness, incisional, 1-to 21-day human upper arm and lower leg skin wounds obtained from 30 healthy volunteers, average age 64±8 years (mean±SD). Wound tissue was either 1⁄2 Karnovsky's-fixed, PolyBed®-embedded and Richardson'sstained or Carnoy-fixed, paraffin-embedded and hematoxylin and eosin-stained. All wounds were obtained in accordance with the Declaration of Helsinki and the University of Washington Human Subjects Institutional Review Board.