title: Retreatment using a dual mode of low-fluence Q-switched and long-pulse Nd:YAG laser in patients with melasma aggravation after previous therapy.
abstract: BACKGROUND
  Aggravated melasma after treatment is vulnerable to stimulation, can easily deteriorate, and may be distressing without proper management.
  
  
  OBJECTIVE
  To retrospectively assess the effectiveness and safety of combination therapy using low-fluence Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (QSNY) and long-pulse Nd:YAG laser (LPNY) (dual toning) in patients with rebound melasma.
  
  
  METHODS
  A total of 30 patients with aggravated melasma after previous therapy who were treated with dual toning were enrolled. A total of 10 sessions were conducted at 1-week intervals, followed by maintenance treatment. The results were evaluated using the modified Melasma Area and Severity Index (mMASI) and the physician's global assessment (PGA) before and 2 months after completing the 10 treatment sessions.
  
  
  RESULTS
  The baseline mMASI was 10.48 ± 3.64, which significantly decreased to 3.22 ± 1.45 2 months after completing the 10 treatment sessions (p < 0.001). Twenty-four patients (80%) had PGA grade 4 (76-100% improvement) and 6 patients (20%) had PGA grade 3 (51-75% improvement).
  
  
  CONCLUSIONS
  Dual toning may be a safe and effective salvage treatment for patients with aggravated melasma after previous treatment. LPNY may stabilize melasma activity to prevent rebound hyperpigmentation via dermal remodeling.
authors.affiliation: Skyfeel Dermatology Clinic.
authors.forename: Chun Pil
authors.initials: CP
authors.lastname: Choi
authors.forename: Seon Mi
authors.initials: SM
authors.lastname: Yim
authors.forename: Soo Hong
authors.initials: SH
authors.lastname: Seo
authors.forename: Hyo Hyun
authors.initials: HH
authors.lastname: Ahn
authors.forename: Young Chul
authors.initials: YC
authors.lastname: Kye
authors.forename: Jae Eun
authors.initials: JE
authors.lastname: Choi
mesh_terms: D000328:Adult; D044466:Asian People; D003357:Cosmetic Techniques; D005260:Female; D006801:Humans; D053844:Lasers, Solid-State / Q000009:adverse effects / Q000627:therapeutic use*; D028022:Low-Level Light Therapy / Q000379:methods*; D008548:Melanosis / Q000532:radiotherapy*; D008875:Middle Aged; D017060:Patient Satisfaction; D019233:Retreatment; D012189:Retrospective Studies
keywords: Adverse events; Q-switched Nd:YAG laser; long-pulsed Nd:YAG laser; melasma; rebound hyperpigmentation