title: Hair removal on dark-skinned patients with pneumatic skin flattening (PSF) and a high-energy Nd:YAG laser.
abstract: BACKGROUND
  Permanent laser hair removal is normally performed with high-energy densities and associated with acute pain. Pneumatic skin flattening (PSF) is a new technology, which helps to control the pain during laser aesthetic treatments. Based on the gate theory of pain transmission, it activates tactile and pressure skin receptors just before the laser shot to naturally block the transmission of pain to the brain while the laser is activated.
  
  
  OBJECTIVE
  To test the safety, pain reduction, as well as the efficacy of PSF in hair removal on patients with dark skin (mainly skin types IV, V and VI) with a high-energy Nd:YAG laser and without skin chilling.
  
  
  METHODS
  Patients were treated for hair removal with a 1064-nm laser (GentleYAG, Candela) at energy densities of 40-44 J/cm(2). Each patient was treated on both axillae: PSF on one side and without PSF (but with a chiller) on control sites. Pain was evaluated on a 1-10 scale. Hair re-growth was counted after 12 weeks. A second treatment was delivered at that time for additional evaluation of pain and further efficacy evaluation. Post-treatment erythema and adverse effects were also noted.
  
  
  RESULTS
  Pain reduction was demonstrated in all 28 patients: the average was 2.6 with PSF and 4.5 without PSF. Hair removal efficacy with and without PSF was identical: 78-79% hair reduction after 12 weeks (standard deviation 14% and 10% respectively, t-test: 0.78). There were no cases of adverse effects and post-treatment erythema was consistently lower with PSF. All patients preferred PSF over non-PSF treatment.
  
  
  CONCLUSIONS
  The PSF technology considerably reduces pain in hair removal with high-energy Nd:YAG lasers on dark skins without side effects, while preserving efficacy. Analgesic creams and skin chilling are not required.
authors.affiliation: Centre Laser Dermatologie Phlebologie, Clapiers, France. nathalie-fournier@wanadoo.fr
authors.forename: Nathalie
authors.initials: N
authors.lastname: Fournier
mesh_terms: D001365:Axilla; D006204:Hair Removal / Q000009:adverse effects* / Q000379:methods*; D006801:Humans; D028022:Low-Level Light Therapy / Q000379:methods*; D010146:Pain / Q000517:prevention & control*; D017060:Patient Satisfaction; D012867:Skin