BackgroundDifferent therapies have been used for dissecting cellulitis of the scalp (DCS) with poor results. Topical 5-aminolaevulinic acid photodynamic therapy (ALA-PDT) is effective for many inflammatory skin diseases. ObjectivesTo evaluate the efficacy and safety of fire micro-needling plus 5% ALA-PDT on DCS. MethodsForty-two male DCS patients were enrolled and treated by four sessions of fire micro-needling plus 5% ALA-PDT (occlusion time: 3 h, 100 mW/cm2 for 20–32 min, 633 ± 10 nm LED) with an interval of 1–2 weeks. The reduction of lesions was evaluated at each follow-up visit. The patients` symptoms were evaluated by Dermatology Life Quality Index (DLQI). All of the side effects were recorded. ResultsForty-one DCS patients finished the treatments and the marked effective rate (MER) reached 65.85%. Ten patients (24.39%) were cured and 17 patients (41.46%) achieved excellent improvement. The median of lesion numbers decreased significantly from 25 to 7 (p < 0.001) with DLQI from 13 to 2 (p < 0.001). Although all the ten cured patients had a relapse during the 12-month follow-up, 5/10 patients had a remission of more than 6 months. All the patients tolerated PDT well with mild adverse effects. ConclusionsFire micro-needling plus 5% ALA-PDT is effective for Chinese male DCS patients without the need to take systemic drugs.