title: Investigation of optimal aminolaevulinic acid concentration applied in topical aminolaevulinic acid-photodynamic therapy for treatment of moderate to severe acne: a pilot study in Chinese subjects.
abstract: BACKGROUND
  Aminolaevulinic acid-photodynamic therapy (ALA-PDT) is a novel and effective treatment in acne. However, little is known about the effect of different concentrations of ALA in the treatment of acne in Chinese patients with Fitzpatrick skin type III and IV.
  
  
  OBJECTIVE
  To investigate the efficacy and safety of ALA-PDT in the treatment of moderate to severe acne in Chinese patients and to identify the suitable concentration of topical ALA.
  
  
  METHODS
  One hundred and eighty patients with moderate to severe facial acne were recruited and randomly divided into four groups. Each group was treated with a different concentration (5%, 10%, 15% and 20%) of ALA to the facial lesions on the right side and placebo agent on the left side as control. Each patient was treated once every 10 days for four sessions. The numbers of inflammatory and noninflammatory acne lesions were counted at baseline and at weeks 2, 4, 12 and 24 after the last treatment. Adverse effects were recorded at each follow-up visit.
  
  
  RESULTS
  After 24 weeks, each side treated by ALA-PDT showed clinical improvement compared with the control side treated by red light alone (P < 0·01). Statistically significantly more patients treated with 20% ALA than with 15% or 10% ALA achieved complete clearance. Regarding side-effects, a trend towards more serious erythema and pigmentation was observed with increasing ALA concentration.
  
  
  CONCLUSIONS
  Increasing the concentration of ALA seems to be beneficial for improving the results. Considering effectiveness and safety, ALA-PDT using 10% or 15% ALA is suggested to the ideal treatment for moderate to severe acne in Chinese patients with Fitzpatrick skin type III and IV.
authors.affiliation: Department of Dermatology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: R
authors.initials: R
authors.lastname: Yin
authors.forename: F
authors.initials: F
authors.lastname: Hao
authors.forename: J
authors.initials: J
authors.lastname: Deng
authors.forename: X C
authors.initials: XC
authors.lastname: Yang
authors.forename: H
authors.initials: H
authors.lastname: Yan
mesh_terms: D000152:Acne Vulgaris / Q000188:drug therapy* / Q000473:pathology; D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000622:Aminolevulinic Acid / Q000008:administration & dosage / Q000627:therapeutic use*; D044466:Asian People; D004305:Dose-Response Relationship, Drug; D005145:Face / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D010865:Pilot Projects; D055815:Young Adult
chemical_list: D017319:Photosensitizing Agents; D000622:Aminolevulinic Acid