Topical photodynamic therapy with porphyrin precursors--assessment of treatment-associated pain in a retrospective study.

Photodynamic therapy (PDT) with aminolevulinic acid (ALA) or methyl aminolevulinate (MAL) is an approved modality for the non-invasive treatment of actinic keratoses (AK) and basal cell carcinoma (BCC) offering excellent cosmetic outcome. However, pain during and after illumination is the most frequent and limiting side effect. The aim of this study was to precisely assess how reported pain during PDT is influenced by sex, age, treatment site, disease (AK/BCC) as well as the photosensitizer used.