title: Psychological stress has the potential to cause a decline in the epidermal permeability barrier function of the horny layer.
abstract: OBJECTIVE
  Psychological stress is known to have a negative effect on a large number of skin diseases. However, there is little research on the relationship between psychological stress and the epidermal permeability barrier function (EPBF) of healthy individuals. We hypothesize that psychological stress deteriorates EPBF and aimed to investigate this relationship.
  
  
  METHODS
  Psychological stress was assessed using salivary alpha-amylase (sAmy; KIU L(-1) ), and chromogranin A level corrected with total protein (CgAP; pmol mg(-1) protein) as psychological stress biomarkers. Measurements were obtained from 16 healthy female students during two periods of presumed higher stress (final examinations and returning from a long vacation), and a period considered as a control. The EPBF level was evaluated by measuring transepidermal water loss (TEWL; g m(-2)  h(-1) ). The TEWL was measured three times: just before (TEWL [Intact]), immediately after (TEWL [Str]) and 4 h after (TEWL [4 h]) barrier disruption by tape stripping. The rate of barrier disruption was evaluated by comparing the difference between the TEWL [Intact] and the TEWL [Str] (delta-BD: g m(-2)  h(-1) ). The recovery was assessed by comparing the difference between the TEWL [Intact] and TEWL [4 h] (delta-RE: g m(-2)  h(-1) ).
  
  
  RESULTS
  The subjects demonstrated a significant increase in the sAmy value after the long vacation compared with the control. There was no change in the CgAP value between the groups. Meanwhile, the EPBF level showed significant deterioration during both higher stress periods. There was a significant increase in delta-BD and delta-RE after the long vacation.
  
  
  CONCLUSIONS
  The results indicate the possibility that psychological stress causes a decline in EPBF and deterioration in barrier disruption and recovery. Furthermore, it implies a relationship between psychological stress and the exacerbation or protracted healing of skin disease.
authors.affiliation: Department of Dermatology, Faculty of Medicine, Iwate Medical University, 19-1, Uchimaru, Morioka, Iwate, 020-8505, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Fukuda
authors.forename: S
authors.initials: S
authors.lastname: Baba
authors.forename: T
authors.initials: T
authors.lastname: Akasaka
mesh_terms: D004817:Epidermis / Q000503:physiopathology*; D006801:Humans; D013315:Stress, Psychological
keywords: amylase; chromogranin A; epidermal permeability barrier function; psychological stress; transepidermal water loss