title: Raman spectroscopy analysis of the skin of patients with melasma before standard treatment with topical corticosteroids, retinoic acid, and hydroquinone mixture.
abstract: BACKGROUND
  Melasma is an abnormal acquired hyperpigmentation of the face of unknown origin, it is considered a single disease and very little has been found regarding its pathogenesis. It is usually assumed that melasma is due to excessive melanin production, but previous work using Raman spectroscopy showed degraded molecules of melanin in some melasma subjects, which may help to explain the success or failure of the standard therapy.
  
  
  METHODS
  We perform Raman spectroscopy measurements on in vivo skin from melasma patients before treatment to identify the molecular structure of melanin within every melasma lesion. The Raman spectra were grouped according to the treatment response from patient, and the Raman spectra were analyzed.
  
  
  RESULTS
  Raman spectroscopy measurements showed a different molecular structure of the patients who did not respond to treatment, those patients shows atypical Raman skin spectrum with peaks associated with melanin not well defined, which is consistent with molecular degradation and protein breakdown.
  
  
  CONCLUSIONS
  Our results are consistent with our previous work in the sense that melasma patients who do not respond to treatment have an abnormal melanin. We believe it will eventually help to decide the treatment of melasma in clinical dermatology.
authors.affiliation: Dermatology Department, Hospital Central 'Dr. Ignacio Morones Prieto', Autonomous University of San Luis Potosí, San Luis Potosí, México.
authors.forename: B
authors.initials: B
authors.lastname: Moncada
authors.affiliation: Dermatology Department, Hospital Central 'Dr. Ignacio Morones Prieto', Autonomous University of San Luis Potosí, San Luis Potosí, México.
authors.forename: C
authors.initials: C
authors.lastname: Castillo-Martínez
authors.affiliation: Dermatology Department, Hospital Central 'Dr. Ignacio Morones Prieto', Autonomous University of San Luis Potosí, San Luis Potosí, México.
authors.forename: E
authors.initials: E
authors.lastname: Arenas
authors.affiliation: Engineering Division, University of Guanajuato, Guanajuato, México.
authors.forename: F
authors.initials: F
authors.lastname: León-Bejarano
authors.affiliation: School of Sciences, Autonomous University of San Luis Potosí, San Luis Potosí, México.
authors.forename: M G
authors.initials: MG
authors.lastname: Ramírez-Elías
authors.affiliation: Coordination for the Innovation and the Application of Science and Technology, Autonomous University of San Luis Potosí, San Luis Potosí, México.
authors.forename: F J
authors.initials: FJ
authors.lastname: González
mesh_terms: D000279:Administration, Cutaneous; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D003879:Dermatologic Agents / Q000008:administration & dosage; D004338:Drug Combinations; D005260:Female; D006801:Humans; D006873:Hydroquinones / Q000008:administration & dosage*; D007641:Keratolytic Agents / Q000008:administration & dosage; D008297:Male; D008543:Melanins / Q000032:analysis / Q000737:chemistry*; D008548:Melanosis / Q000188:drug therapy* / Q000378:metabolism; D008875:Middle Aged; D012867:Skin / Q000737:chemistry* / Q000187:drug effects; D013059:Spectrum Analysis, Raman / Q000379:methods; D016896:Treatment Outcome; D014212:Tretinoin / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D000893:Anti-Inflammatory Agents; D003879:Dermatologic Agents; D004338:Drug Combinations; D006873:Hydroquinones; D007641:Keratolytic Agents; D008543:Melanins; D014212:Tretinoin; C031927:hydroquinone
keywords: Raman spectroscopy; melanin; melasma; solar elastosis