Is the pain of topical photodynamic therapy with methyl aminolevulinate any different from that with 5‐aminolaevulinic acid?

Summary Topical photodynamic therapy ( PDT ) using 5‐aminolaevulinic acid ( ALA ) or methyl aminolevulinate ( MAL ) is widely used in dermatology. It is commonly stated that MAL PDT is less painful than ALA PDT , although published data are conflicting. We report our experience of the use of ALA (4–6 h) ( n  = 20) and MAL (3 h) ( n  = 20) in 40 consecutive patients with Bowen's disease or superficial basal cell carcinoma, treated with PDT using an identical irradiation regime. Although there was a trend to higher pain scores with ALA PDT [visual analogue scale ( VAS )score, median 4.50], this was not significantly different from that of MAL PDT ( VAS score, median 3.55; P  = 0.98), nor considered to be clinically important. Importantly, both ALA and MAL PDT regimes were fairly well tolerated in this patient cohort, supporting the use of these prodrugs in dermatological PDT .