title: Regional variations in percutaneous absorption.
abstract: BACKGROUND
  In its simplest definition, percutaneous absorption (PA) is the amount of substance that passes through the stratum corneum compared with the amount applied. The study of the PA of substances is relevant to the fields of dermatopharmacology and occupational medicine. The quantity and rate in which a given chemical absorbs through the skin depend on a multitude of variables. One obvious determinant of PA is the application site. This overview summarizes currently available data on the topic of regional variations in PA and possibly suggests a direction for future research efforts.
  
  
  METHODS
  Searches were performed in Medline and EMBASE. Extensive bibliographical research was performed in order to identify additional relevant data sets using Web of Science. Results were screened for inclusion of more than one anatomical site, the use of validated methods, and the use of human subjects.
  
  
  RESULTS
  We identified eight relevant studies, from which we present data.
  
  
  CONCLUSIONS
  Determining regional variations in PA is a complex yet critically important task. Current data sets are scarce and inadequate for drawing complete conclusions, but the data seem to suggest increased PA in the forehead and genital skin compared with other anatomical regions. It is our hope that, with the advent of new technologies, an anatomical PA map will begin to emerge from the data. Such descriptive understanding will guide investigation into the mechanisms involved in determining anatomical site differences in PA.
authors.affiliation: Department of Dermatology, University of California Davis, Sacramento, CA, USA.
authors.forename: Hadar
authors.initials: H
authors.lastname: Lev-Tov
authors.forename: Howard I
authors.initials: HI
authors.lastname: Maibach
mesh_terms: D005546:Forehead / Q000502:physiology; D005835:Genitalia / Q000502:physiology; D006801:Humans; D012869:Skin Absorption / Q000502:physiology*