title: Skin pH, atopic dermatitis, and filaggrin mutations.
abstract: BACKGROUND
  The acidic pH of the skin plays a role in antimicrobial defense by regulating the bacterial skin flora and aspects of barrier. Filaggrin is a co-factor in maintaining a low skin pH because of its degradation into acidic amino acids. Accordingly, lack of filaggrin due to filaggrin mutations may influence skin pH.
  
  
  OBJECTIVE
  We aimed to determine the epidermal pH in different groups stratified by filaggrin mutations and atopic dermatitis. Further, we investigated the changes in pH according to severity of mutational status among patients with dermatitis, irrespective of skin condition.
  
  
  METHODS
  pH was measured with a multiprobe system pH probe (PH 905), and the study population was composed of 67 individuals, who had all been genotyped for 3 filaggrin mutations (R501X, 2282del4, R2447X).
  
  
  RESULTS
  We found no clear pattern in relation to filaggrin mutation carrier status. Individuals with wild-type filaggrin displayed both the most acidic and most alkaline values independent of concomitant skin disease; however, no statistical differences between the groups were found.
  
  
  CONCLUSIONS
  The lack of significant diversity in skin pH in relation to filaggrin mutation carrier status suggests that the effect of filaggrin mutations on skin pH is not pronounced.
authors.affiliation: From the *Department of Dermato-Allergology, National Allergy Research Centre, Copenhagen University Hospital Gentofte, Hellerup; *Department of Nuclear Medicine, Aalborg University Hospital, and **Department of Clinical Medicine, Aalborg University, Denmark.
authors.forename: Josefine
authors.initials: J
authors.lastname: Bandier
authors.forename: Jeanne Duus
authors.initials: JD
authors.lastname: Johansen
authors.forename: Lars Jelstrup
authors.initials: LJ
authors.lastname: Petersen
authors.forename: Berit Christina
authors.initials: BC
authors.lastname: Carlsen
mesh_terms: D000328:Adult; D004252:DNA Mutational Analysis; D003718:Denmark; D003876:Dermatitis, Atopic / Q000235:genetics*; D005260:Female; D000091344:Filaggrin Proteins; D005838:Genotype; D006229:Hand Dermatoses / Q000235:genetics*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007381:Intermediate Filament Proteins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012867:Skin / Q000737:chemistry; D012882:Skin Tests; D055815:Young Adult
chemical_list: C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D007381:Intermediate Filament Proteins