title: Photodynamic treatment of oral lichen planus.
abstract: OBJECTIVE
  The aim of this study was to examine the clinical behavior and response to topical methyl 5-aminolevulinate (MAL) photodynamic therapy (PDT) of oral lichen planus and to describe the buildup and biodistribution of photoactive porphyrins in normal and lichen planus-affected oral mucosa after MAL application.
  
  
  METHODS
  The difference in clinical expression in 14 patients with buccal oral lichen planus was compared before and after treatment. MAL-induced photoactive porphyrins were monitored using noninvasive in situ fluorescence measurements. Microfluorometry was used to study the biodistribution.
  
  
  RESULTS
  The absorption and conversion of protoporphyrin IX (PpIX) in epithelial and subepithelial T cells was demonstrated in histologic sections. As a result of 1 treatment session, there was a significant improvement of oral lichen planus after 6 months (P = 0.02) and during a 4-year follow-up period.
  
  
  CONCLUSIONS
  MAL is absorbed and converted to PpIX in T cells. Oral lichen planus treated with MAL-PDT showed lasting improvement after a single treatment.
authors.affiliation: Institute of Clinical Dentistry, Faculty of Dentistry, University of Oslo, Oslo, Norway. skvaal@odont.uio.no
authors.forename: Sigrid I
authors.initials: SI
authors.lastname: Kvaal
authors.forename: Even
authors.initials: E
authors.lastname: Angell-Petersen
authors.forename: Trond
authors.initials: T
authors.lastname: Warloe
mesh_terms: D000622:Aminolevulinic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D003592:Cytophotometry; D005260:Female; D006801:Humans; D017676:Lichen Planus, Oral / Q000188:drug therapy*; D008297:Male; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D017319:Photosensitizing Agents; C475457:methyl 5-aminolevulinate; D000622:Aminolevulinic Acid