Plum-blossom needle tapping enhances the efficacy of ALA photodynamic therapy for facial actinic keratosis in Chinese population: a randomized, multicenter, prospective, and observer-blind study

•Photodynamic therapy (PDT) with 5-aminolevulinate (ALA) is a reliable treatment for Actinic keratosis (AK) but the effect needs to be enhanced in thick lesions.•Plum-blossom needle is a traditional Chinese economical instrument for enhancing transdermal delivery of ALA.•This multicenter and prospective study compared the efficacy and safety of Plum-blossom needle assist PDT in facial AK in Chinese population.•Plum-blossom needle tapping may enhance the efficacy of ALA-PDT by facilitating ALA delivery in the treatment of AK.