title: Basis of occlusive therapy in psoriasis: correcting defects in permeability barrier and calcium gradient.
abstract: BACKGROUND
  Although occlusive dressings have great potential in the management of psoriasis vulgaris, the therapeutic mechanism is not completely understood. Occlusion artificially restores and corrects the defective barrier in psoriasis plaques. Additionally, occlusion is know to normalize the epidermal calcium gradients in hyperproliferative murine skin models.
  
  
  METHODS
  To investigate the basis of the therapeutic effect of occlusion on psoriatic plaques, we investigated the ultrastructural morphology of intercorneocyte lipid layers, lamellar bodies, and calcium gradient in chronic plaque-type psoriasis after occlusion with a water vapor-impermeable membrane. The specimens were processed for electron microscopy using: (i) ruthenium tetroxide postfixation; and (ii) ion-capture cytochemistry for calcium localization.
  
  
  RESULTS
  Occlusion for 7 days resulted in a nearly mature pattern of intercellular multilamellar structures, re-establishment of the near-normal epidermal calcium gradient, and disappearance of calcium precipitates from the stratum corneum interstices.
  
  
  CONCLUSIONS
  The normalization of the permeability barrier and epidermal calcium gradient may play important roles in the therapeutic effects of occlusive dressings in chronic plaque-type psoriasis.
authors: Department of Dermatology, Yonsei University Wonju College of Medicine, Wonju, South Korea.
authors: S M
authors: SM
authors: Hwang
authors: S K
authors: SK
authors: Ahn
authors: G K
authors: GK
authors: Menon
authors: E H
authors: EH
authors: Choi
authors: S H
authors: SH
authors: Lee
mesh_terms: D002118:Calcium / Q000378:metabolism; D006801:Humans; D008854:Microscopy, Electron; D009779:Occlusive Dressings; D010539:Permeability; D011565:Psoriasis / Q000473:pathology / Q000628:therapy*; D012867:Skin / Q000378:metabolism / Q000503:physiopathology / Q000648:ultrastructure; D016896:Treatment Outcome
chemical_list: D002118:Calcium