title: Effect of retinoid pretreatment on outcomes of patients treated by photodynamic therapy for actinic keratosis of the hand and forearm.
abstract: OBJECTIVE
  Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) has been shown to be useful in both spot and field treatments of actinic keratoses (AK). This study evaluates the safety and efficacy of pretreatment of AK lesions on the dorsal hands and forearms with tazarotene gel (0.1%) twice a day for one week before broad-area ALA PDT.
  
  
  METHODS
  Ten subjects aged 75.4 ± 11.6 years (mean plus minus SD) with at least four AK lesions on their dorsal forearm or hand were randomized so that one dorsal hand or forearm was pretreated with tazarotene gel (0.1%) twice daily for one week before ALA PDT with blue light. The other hand or forearm (control) was not pretreated. After seven days, ALA was applied to both sides and incubated 60 minutes before irradiation with blue light. ALA was applied first only to the AK lesions and then to the entire treatment area (defined as the extensor surface of the hand or forearm between the elbow and the base of the fingers) before 60-minute incubation. The ALA area on the control side was occluded during the 60-minute incubation. Efficacy and adverse effects were evaluated within 48 hours and eight weeks later.
  
  
  RESULTS
  For both the pretreated and control group, lesion counts of the target areas decreased significantly from baseline to eight weeks after ALA PDT. Reduction percentages of the target area, however, did not differ significantly between the two groups. When reduction percentages of the entire treatment area for both groups were compared the difference between the two groups was of borderline significance (P=0.0547). When the entire treatment area was analyzed, lesion counts of the tazarotene group differed significantly from baseline at eight weeks (P=0.0002), but this was not the case with the control group (P=0.0365). Adverse events were limited to those expected after ALA PDT. Erythema was significantly more severe (P=0.0029) in the pretreated arm five minutes after ALA PDT.
  
  
  CONCLUSIONS
  Pretreatment of AK lesions on the dorsal hand and forearm with tazarotene gel (0.1%) may enhance the therapeutic effect of ALA PDT without serious side effects.
authors.affiliation: Private Practice, Dermatologic Laser and Surgery Center, Fort Lauderdale, FL, USA. derm@galitzer.com
authors.forename: Barry I
authors.initials: BI
authors.lastname: Galitzer
mesh_terms: D000279:Administration, Cutaneous; D000368:Aged; D000369:Aged, 80 and over; D000622:Aminolevulinic Acid / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D003879:Dermatologic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D004890:Erythema / Q000209:etiology; D005260:Female; D005542:Forearm; D005782:Gels; D006229:Hand Dermatoses / Q000188:drug therapy / Q000473:pathology; D006801:Humans; D055623:Keratosis, Actinic / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009539:Nicotinic Acids / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D010778:Photochemotherapy / Q000009:adverse effects / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome; D012176:Retinoids
chemical_list: D000622:Aminolevulinic Acid; D003879:Dermatologic Agents; D005782:Gels; D009539:Nicotinic Acids; D017319:Photosensitizing Agents; C086827:tazarotene; D012176:Retinoids