title: Different effects of pimecrolimus and betamethasone on the skin barrier in patients with atopic dermatitis.
abstract: BACKGROUND
  Genetic defects leading to skin barrier dysfunction were recognized as risk factors for atopic dermatitis (AD). It is essential that drugs applied to patients with AD restore the impaired epidermal barrier to prevent sensitization by environmental allergens.
  
  
  OBJECTIVE
  We investigated the effect of 2 common treatments, a calcineurin inhibitor and a corticosteroid, on the skin barrier.
  
  
  METHODS
  In a randomized study 15 patients with AD were treated on one upper limb with pimecrolimus and on the other with betamethasone twice daily for 3 weeks.
  
  
  RESULTS
  Stratum corneum hydration and transepidermal water loss, a marker of the inside-outside barrier, improved in both groups. Dye penetration, a marker of the outside-inside barrier, was also reduced in both drugs. Electron microscopic evaluation of barrier structure displayed prevalently ordered stratum corneum lipid layers and regular lamellar body extrusion in pimecrolimus-treated skin but inconsistent extracellular lipid bilayers and only partially filled lamellar bodies after betamethasone treatment. Both drugs normalized epidermal differentiation and reduced epidermal hyperproliferation. Betamethasone was superior in reducing clinical symptoms and epidermal proliferation; however, it led to epidermal thinning.
  
  
  CONCLUSIONS
  The present study demonstrates that both betamethasone and pimecrolimus improve clinical and biophysical parameters and epidermal differentiation. Because pimecrolimus improved the epidermal barrier and did not cause atrophy, it might be more suitable for long-term treatment of AD.
authors.affiliation: Department of Dermatology, University of Kiel, Kiel, Germany.
authors.forename: Jens-Michael
authors.initials: JM
authors.lastname: Jensen
authors.forename: Stephan
authors.initials: S
authors.lastname: Pfeiffer
authors.forename: Magdalena
authors.initials: M
authors.lastname: Witt
authors.forename: Matthias
authors.initials: M
authors.lastname: Bräutigam
authors.forename: Claudia
authors.initials: C
authors.lastname: Neumann
authors.forename: Michael
authors.initials: M
authors.lastname: Weichenthal
authors.forename: Thomas
authors.initials: T
authors.lastname: Schwarz
authors.forename: Regina
authors.initials: R
authors.lastname: Fölster-Holst
authors.forename: Ehrhardt
authors.initials: E
authors.lastname: Proksch