title: Gain with no pain? Pain management in dermatological photodynamic therapy.
abstract: Pain during photodynamic therapy (PDT) is the main limiting adverse effect in its use in dermatology. Given its multifactorial nature, we reviewed both intrinsic and extrinsic factors that are involved in PDT pain. We propose a threshold theory for pain experience in PDT: it correlates positively with fluence rate and dose below a certain threshold (rate of ~60 mW cm-2, dose of ~50 J cm-2); when the threshold is surpassed, pain intensity saturates. Additionally, we carefully compared recent updates on pain management strategies and we suggest that cold-air analgesia and low-irradiance light sources (such as variable pulsed light and daylight PDT) represent the current best analgesic options. Finally, we discuss the possible mechanisms of pain experience during PDT. Reactive oxygen species, transient receptor potential channels and inflammatory responses are key mediators in pain. Further investigation into these pathways should help with the development of more effective analgesic strategies. Taking these points together, for pain management in PDT, an individualized plan of analgesia is possible.
authors.affiliation: Department of Dermatology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.affiliation: Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, 1278 Baode Road, Shanghai, 200443, China.
authors.forename: L
authors.initials: L
authors.lastname: Shi
authors.affiliation: Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, 1278 Baode Road, Shanghai, 200443, China.
authors.forename: Y F
authors.initials: YF
authors.lastname: Zhang
authors.affiliation: Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, 1278 Baode Road, Shanghai, 200443, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Department of Dermatology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: J
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Department of Dermatology and Allergology, Vest Clinic, Recklinghausen, Germany.
authors.forename: R M
authors.initials: RM
authors.lastname: Szeimies
authors.affiliation: Institute of Photomedicine, Shanghai Skin Disease Hospital, Tongji University School of Medicine, 1278 Baode Road, Shanghai, 200443, China.
authors.forename: X L
authors.initials: XL
authors.lastname: Wang
mesh_terms: D000388:Air; D000700:Analgesics / Q000627:therapeutic use; D014644:Genetic Variation / Q000502:physiology; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods; D009407:Nerve Block / Q000379:methods; D010146:Pain / Q000235:genetics / Q000517:prevention & control*; D059408:Pain Management / Q000379:methods; D017288:Pain Threshold / Q000502:physiology; D010778:Photochemotherapy / Q000009:adverse effects*; D017319:Photosensitizing Agents / Q000009:adverse effects; D011829:Radiation Dosage; D017382:Reactive Oxygen Species / Q000378:metabolism; D012871:Skin Diseases / Q000188:drug therapy* / Q000235:genetics; D050051:Transient Receptor Potential Channels / Q000378:metabolism
chemical_list: D000700:Analgesics; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D050051:Transient Receptor Potential Channels