title: Estriol induced squamous metaplasia on the nasal mucosa in patients with hereditary hemorrhagic telangiectasia.
abstract: BACKGROUND
  The aim of this study was to evaluate by light and electron microscopy the effect of topical estriol on the nasal mucosa in patients with hereditary hemorrhagic telangiectasia (HHT).
  
  
  METHODS
  Twelve patients were instructed to apply twice daily 0.1% estriol as a nose ointment over a period of 12 months. Written consent was obtained from each patient, allowing biopsy specimens of the nasal mucosa to be taken prior to and 3, 6 and 12 months after estriol application.
  
  
  RESULTS
  Metaplastic change of the nasal mucosa was observed 6 months after topical estriol application. The former ciliated columnar epithelium changed into a keratinizing squamous epithelium. The effect was reversible after discontinuation of estriol application.
  
  
  CONCLUSIONS
  For the first time, we could outline the effect of topical estriol on the nasal mucosa. These histomorphological findings, and the fact that estriol is a low-potency metabolite of estradiol, make estriol a valuable agent in the treatment of HHT patients.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, University Hospital Manheim, Germany. haneen.sadick@hno.ma.uni-heidelberg.de
authors.forename: Haneen
authors.initials: H
authors.lastname: Sadick
authors.forename: Wolfgang F
authors.initials: WF
authors.lastname: Bergler
authors.forename: Jasmina
authors.initials: J
authors.lastname: Oulmi-Kagermann
authors.forename: Ramin
authors.initials: R
authors.lastname: Naim
authors.forename: Maliha
authors.initials: M
authors.lastname: Sadick
authors.forename: Karl
authors.initials: K
authors.lastname: Hörmann
authors.forename: Frank
authors.initials: F
authors.lastname: Riedel
mesh_terms: D000287:Administration, Topical; D001706:Biopsy; D004964:Estriol / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D009297:Nasal Mucosa / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D009824:Ointments; D013683:Telangiectasia, Hereditary Hemorrhagic / Q000188:drug therapy* / Q000473:pathology
chemical_list: D009824:Ointments; D004964:Estriol