title: Treatment with 5-aminolaevulinic acid methylester is less painful than treatment with 5-aminolaevulinic acid nanoemulsion in topical photodynamic therapy for actinic keratosis.
abstract: BACKGROUND
  Topical photodynamic therapy (PDT) is an excellent treatment option for actinic keratosis (AK). Pain is one of the major adverse effects.
  
  
  OBJECTIVE
  To compare the pain intensity during the extensive treatment of cosmetic units using 5-aminolaevulinic acid methylester (MAL) or 5-aminolaevulinic acid nanoemulsion (BF-200-ALA).
  
  
  METHODS
  173 patients with 965 treated areas were enrolled in this retrospective monocentric study. All patients had multiple AKs and received an extensive treatment of the photodamaged area. 424 areas were treated with MAL and 541 with BF-200-ALA. Pain was rated using a standardized visual analogue scale (VAS). The number of PDT treatment interruptions was documented.
  
  
  RESULTS
  PDT with MAL led to a lower mean VAS score (5.0 vs. 5.8), a lower number of treatment interruptions (13.2 vs. 19.9%) and a lower amount of patients experiencing severe pain (25.0 vs. 36.0%) compared to PDT with BF-200-ALA.
  
  
  CONCLUSIONS
  Our data shows that PDT using MAL is less painful than PDT using BF-200-ALA resulting in a significantly lower mean VAS score (p < 0.001), significantly fewer patients experiencing severe pain (p < 0.001) and a significantly (p < 0.05) lower number of treatment interruptions. Differences in selectivity for tumour cells and transport of ALA in peripheral neurons may play a role.
authors.affiliation: Department of Dermatology, University of Heidelberg, Heidelberg, Germany. patrick.gholam@med.uni-heidelberg.de
authors.forename: Patrick
authors.initials: P
authors.lastname: Gholam
authors.forename: Tanja
authors.initials: T
authors.lastname: Weberschock
authors.forename: Katharina
authors.initials: K
authors.lastname: Denk
authors.forename: Alexander
authors.initials: A
authors.lastname: Enk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000622:Aminolevulinic Acid / Q000009:adverse effects* / Q000031:analogs & derivatives* / Q000627:therapeutic use; D004655:Emulsions / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D055623:Keratosis, Actinic / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D050997:Nanomedicine; D010146:Pain / Q000139:chemically induced*; D010147:Pain Measurement; D010778:Photochemotherapy / Q000009:adverse effects; D017319:Photosensitizing Agents / Q000009:adverse effects / Q000627:therapeutic use; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D004655:Emulsions; D017319:Photosensitizing Agents; C114767:delta-aminolevulinic acid methyl ester; D000622:Aminolevulinic Acid