title: Effect of topical tretinoin on epidermal Langerhans' cells in photodamaged skin.
abstract: BACKGROUND
  Topical tretinoin has been successfully applied to treat photoaging; however, a decrease in the number of Langerhans' cells (LC) has been reported after its topical application in Macaque skin. A study was performed to evaluate the possible effect of topical tretinoin on the number of LC in human beings.
  
  
  METHODS
  Eight patients were studied. Topical tretinoin was applied in progressively increasing concentrations: 0.025% for 1 month, 0.05% for one month and 0.1% for 4 months. A skin biopsy from the malar area was taken before this therapy and 6 months later. To study LC, 4 mu frozen sectionswere stained with the anti-CD1 antibody.
  
  
  RESULTS
  The number of CD1+ cells did not change when they were counted per unit of epidermal length, but they decreased when they were counted per unit of epidermal surface.
  
  
  CONCLUSIONS
  These results indicate that topical tretinoin might damage epidermal Langerhans' cells, when it is applied for long periods of time; future studies are necessary to clarify this point.
authors.affiliation: Department of Dermatology, Hospital de la Sta. Creu i Sant Pau, Bacelona, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Barnadas
authors.forename: R
authors.initials: R
authors.lastname: Curell
authors.forename: J M
authors.initials: JM
authors.lastname: Moragas
mesh_terms: D000287:Administration, Topical; D000368:Aged; D018949:Antigens, CD1 / Q000032:analysis; D002452:Cell Count; D005260:Female; D006801:Humans; D007801:Langerhans Cells / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015595:Skin Aging / Q000276:immunology / Q000473:pathology*; D014212:Tretinoin / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D018949:Antigens, CD1; D014212:Tretinoin