title: An assessment of the human nail plate pH.
abstract: OBJECTIVE
  To measure the pH of the surface of healthy nail plates.
  
  
  METHODS
  The surface pH of human fingernails and big toenails was measured in vivo using a skin pH meter. The influence of washing, anatomical site (fingers/toes), side (left/right), digit (digits 1-5) and gender was determined. The pH of the nail interior was also measured.
  
  
  RESULTS
  The pH of the nail plate surface was around 5, with toenails having a significantly higher pH than fingernails. Immediately after hand washing, the nail surface pH increased significantly, from pH 5.1 ± 0.4 to 5.3 ± 0.5. However, this was not sustained with time, and the pH returned to prewashing levels within 20 min. Gender had an influence on unwashed, but not washed, nail plate pH. The pH of the nail plate interior was lower than that of its surface.
  
  
  CONCLUSIONS
  It was possible to measure nail plate pH, and baseline values are provided.
authors.affiliation: Department of Pharmaceutics, The School of Pharmacy, University of London, London, UK. sudax.murdan@pharmacy.ac.uk
authors.forename: S
authors.initials: S
authors.lastname: Murdan
authors.forename: G
authors.initials: G
authors.lastname: Milcovich
authors.forename: G S
authors.initials: GS
authors.lastname: Goriparthi
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005385:Fingers; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D009262:Nails / Q000378:metabolism*; D011446:Prospective Studies; D014034:Toes; D055815:Young Adult