Pain during topical photodynamic therapy - comparing methyl aminolevulinate (Metvix®) to aminolaevulinic acid (Ameluz®); an intra-individual clinical study

Background: Actinic keratoses are often treated by photodynamic therapy. However, the main side effect of this treatment is pain during and shortly after illumination. Objectives: To evaluate, in an intra-individual study, whether the pain response differ in treatment of actinic keratoses in scalp and forhead, using branded methyl aminolevulinate (MAL) and aminolaevulinic acid (ALA). Materials and methods: Patients with mild to moderate actinic keratoses on forehead and scalp were treated with methyl aminolaevulinate (MAL)-PDT and aminolaevulinic acid (ALA)-PDT on two similar areas of forehead and scalp. The pain response were measured using visual analogue scale ranging from 0 to 10 during the illumination and 30 min after the treatment. Results: Fourteen patients completed treatment to MAL and ALA-PDT. We found no significant difference in pain intensity between MAL and ALA-PDT, neither during the treatment (p-value = 1) nor 30 min after the treatment (p-value of 0.19). Conclusions: This infra-individual study demonstrate no significant difference between the pain response during PDT using methyl aminolevulinate and aminolaevulinic acid.