title: Efficacy of red light alone and methyl-aminolaevulinate-photodynamic therapy for the treatment of mild and moderate facial acne.
abstract: BACKGROUND
  Photodynamic therapy (PDT) has been shown to be an effective alternative for acne. However, there is little information comparing the efficacy of red light alone and methyl aminolaevulinate (MAL)-PDT.
  
  
  OBJECTIVE
  To compare the efficacy and tolerability of red light alone and MAL-PDT in patients with mild to moderate facial acne.
  
  
  METHODS
  Thirty six patients with mild to moderate acne were enrolled. Eighteen patients recieved MAL-PDT and 18 received red light alone in two sessions, 2 weeks apart. Acne grade and lesion counts were assessed by blinded evaluators at baseline, 2, 4 and 10 weeks.
  
  
  RESULTS
  At week 2, clinical improvement from acne grade II-IV to 0-I was observed in 82.3% of MAL-PDT group and 14.2% of red light alone group. Red light alone group had a gradual clinical improvement over time with a 77% response at week 10. In contrast, MAL-PDT group had a rapid clinical improvement with total response at week 10. Both treatments were significantly effective for improving acne lesions. However, MAL-PDT group had a greater response (P < 0.001). Histologically, decreased amounts of sebocytes and lipids along with atrophic sebaceous glands were observed after MAL-PDT.
  
  
  CONCLUSIONS
  MAL-PDT has a quicker onset of action with a higher response than red light alone. MAL-PDT may induce a reduction in the size of the sebaceous glands and then long-term acne remission.
authors.affiliation: Department of Medical Specialties, Facultad de Medicina, Universidad de La Frontera, Temuco, Chile.
authors.forename: Cristian
authors.initials: C
authors.lastname: Pinto
authors.forename: Fabiola
authors.initials: F
authors.lastname: Schafer
authors.forename: Juan Jose
authors.initials: JJ
authors.lastname: Orellana
authors.forename: Sergio
authors.initials: S
authors.lastname: Gonzalez
authors.forename: Ariel
authors.initials: A
authors.lastname: Hasson
mesh_terms: D000152:Acne Vulgaris / Q000188:drug therapy*; D000293:Adolescent; D000328:Adult; D000622:Aminolevulinic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005145:Face; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D017319:Photosensitizing Agents; C475457:methyl 5-aminolevulinate; D000622:Aminolevulinic Acid