title: High intensity focused ultrasound as a potential new modality for the treatment of pigmentary skin disorder.
abstract: OBJECTIVE
  The clinical skin tightening benefits of high intensity focused ultrasound (HIFU) have been established, but its mechanism of action in pigmented skin disorders remains unknown. We macroscopically and histopathologically investigated dermatological changes after HIFU at different exposure doses in a UVB-induced guinea pig model of hyperpigmentation.
  
  
  METHODS
  We applied HIFU irradiation at 0.1 and 0.2 J/cm(2) to UVB-induced spotty hyperpigmentation in guinea pig skin. The therapeutic effects of HIFU were judged based on gross appearance using photography, dermoscopy, and chromametry during a period of 3 weeks after HIFU irradiation. Histological assessments were performed using Fontana-Masson staining 1 day before and 3 weeks after HIFU irradiation.
  
  
  RESULTS
  Macroscopically, UVB-induced hyperpigmentation was significantly reduced 2 weeks after HIFU with 0.2 J/cm(2) , and 3 weeks after HIFU with 0.1 J/cm(2) . Histopathologically, the heavy deposition of melanin in the epidermis induced by UVB exposure was reduced 3 weeks after HIFU irradiation.
  
  
  CONCLUSIONS
  We confirmed that HIFU has a positive effect on UVB-induced hyperpigmentation as well as mechanical destructive activity. We suggest that HIFU may be useful as an alternative modality for human patients suffering from skin pigmentary conditions.
authors.affiliation: Department of Dermatology, Chung-Ang University College of Medicine, Seoul, South Korea.
authors.forename: S Y
authors.initials: SY
authors.lastname: Choi
authors.affiliation: Department of Dermatology, Catholic Kwandong University International ST.Mary's Hospital, Incheon, South Korea.
authors.forename: K H
authors.initials: KH
authors.lastname: Yoo
authors.affiliation: Department of Dermatology, Chung-Ang University College of Medicine, Seoul, South Korea.|Department of Medicine, Graduate school, Chung-Ang University, Seoul, South Korea.
authors.forename: C T
authors.initials: CT
authors.lastname: Oh
authors.affiliation: Department of Dermatology, Chung-Ang University College of Medicine, Seoul, South Korea.|Department of Medicine, Graduate school, Chung-Ang University, Seoul, South Korea.
authors.forename: T R
authors.initials: TR
authors.lastname: Kwon
authors.affiliation: Department of Medicine, Graduate school, Chung-Ang University, Seoul, South Korea.
authors.forename: E J
authors.initials: EJ
authors.lastname: Choi
authors.affiliation: Department of Dermatology, Chung-Ang University College of Medicine, Seoul, South Korea.
authors.forename: J
authors.initials: J
authors.lastname: Seok
authors.affiliation: Department of Dermatology, Chung-Ang University College of Medicine, Seoul, South Korea.
authors.forename: B J
authors.initials: BJ
authors.lastname: Kim
mesh_terms: D000818:Animals; D005240:Feasibility Studies; D005260:Female; D006168:Guinea Pigs; D057086:High-Intensity Focused Ultrasound Ablation / Q000379:methods*; D010859:Pigmentation Disorders / Q000209:etiology / Q000473:pathology* / Q000628:therapy*; D012880:Skin Pigmentation / Q000528:radiation effects*; D016896:Treatment Outcome; D014466:Ultraviolet Rays / Q000009:adverse effects*
keywords: UVB; high intense focused ultrasound; hyperpigmentation; pigmentation