Randomized, double-blind, placebo-controlled prospective study of the efficacy of topical anaesthesia with a eutetic mixture of lignocaine 2·5% and prilocaine 2·5% for topical 5-aminolaevulinic acid–photodynamic therapy for extensive scalp actinic keratoses


  • Conflicts of interest: None declared.

S.M. Langan.
E-mail: sineadlangan@hotmail.com


Background  Photodynamic therapy (PDT) is an effective treatment modality for the treatment of extensive scalp actinic keratoses (AKs), but pain is a significant drawback when treating large areas with topical PDT using 5-aminolaevulinic acid (ALA) as sensitizer. A recent study has shown that use of tetracaine gel (Ametop®) did not significantly reduce pain associated with PDT.

Objectives  To assess the benefit of a eutetic mixture of lignocaine 2·5% and prilocaine 2·5% (Emla®) on pain during topical ALA–PDT treatment of scalp AKs.

Methods  Fourteen men aged 59–83 years with extensive scalp AKs were recruited into a double-blind placebo-controlled study. Two treatment fields were defined (right and left frontal scalp) and were treated 2 weeks apart. These fields were randomized to receive either Emla® or Aqueous cream as first or second treatment. ALA 20% cream was applied for 4 h. Topical anaesthesia or Aqueous cream was applied for 2 h. Pain was assessed using a visual analogue scale (0–100 mm) at 3, 6, 12 and 16 min. The instrument used for this was a blinded counter with one side reading ‘no pain’ to ‘worst pain ever’ with a numerical scale (0–100) on the reverse side. Pain scores were assessed looking at median and interquartile range and confidence intervals and calculating differences between treatment groups and analysing them using a paired t-test.

Results  Thirteen patients received treatment to both fields. No significant difference in mean pain scores was seen with the use of Emla® cream compared with placebo during treatment of scalp AKs (P = 0·328). There was no significant difference in requirement for oral analgesia following PDT between the two groups (P = 0·06).

Conclusions  Our data do not support the routine use of topical anaesthesia with Emla® for topical PDT.