Cold air in laser therapy: First experiences with a new cooling system

Background and Objective: Analgesic cooling technologies are firmly establi shed in dermatologic laser therapy. We present cold air as a novel method o f cooling and compare it with those methods that are already in use. Study Design/Materials and Methods: We treated 166 patients with the diagno ses hypertrichosis, port wine stains, hemangioma, essential telangiectasias , and tattoos with different laser systems (long-pulsed alexandrite laser [ LPIR], pulsed dye laser, Q-switched Nd:YAG laser, Q-switched ruby laser). I n a prospective study, we collected data about the analgesia of the cooling method and the thermal protection of the epidermis (reduction of the exten t and duration of erythema, purpura, blisters, hyper-/hypopigmentations, ed emas, crusting), compared with the cooling method with ice gel. Additionall y, we measured air and shin temperatures with an infrared thermometer at di fferent application modalities. Results: Three percent of the treated patients refused the cold air therapy altogether. Eleven percent found that it was as good as the other cooling methods; 86% clearly preferred the cold air therapy. Leaving out the perina sal area, the percentage rises to 97%. On average, the analgesic effect was by 37% better than through cooling with ice gel. The increased thermal pro tection of the epidermis made it possible to use laser energy levels that w ere higher by 15-30% and, at the same time, to reduce the rate of side effe cts (in 63% of the patients erythema persisted for a shorter period, in 70% the purpura was reduced, 83% had less crusting). Conclusion: In dermatologic laser therapy, the use of cold air in analgesia can be considered as an effective, inexpensive, and well-accepted (by both patients and doctors) alternative to currently applied cooling methods. Ne vertheless, further prospective studies are necessary to determine whether treatment results can really be improved by using higher laser energy level s. Lasers Surg. Med. 27:404-410, 2000. (C) 2000 Wiley-liss, Inc.